Method for transmitting demodulation reference signal for uplink data in wireless communication system, and device for same

ABSTRACT

The present disclosure provides a method for transmitting a demodulation reference signal. Specifically, the method performed by the terminal comprising: receiving, from a base station, a radio resource control (RRC) signaling including control information representing that transform precoding for an uplink is enabled; generating a low peak to average power ratio (PAPR) sequence based on a length-6 sequence; generating a sequence used for the demodulation reference signal based on the low PAPR sequence; and transmitting, to the base station, the demodulation reference signal based on the sequence used for the demodulation reference signal, wherein the length-6 sequence has an 8-Phase Shift Keying (PSK) symbol as each element of the sequence.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Application No. 17/431,259,filed on Aug. 16, 2021, which is National Stage Application under 35U.S.C. § 371 of International Application No. PCT/KR2020/002191, filedFeb. 17, 2020, which claims the benefit of Korean Patent Application No.10-2019-0033971, filed on Mar. 25, 2019, U.S. Provisional ApplicationNo. 62/806,716, filed on Feb. 15, 2019, and Korean Patent ApplicationNo. 10-2019-0017741, filed on Feb. 15, 2019. The disclosures of theprior applications are incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system, andmore particularly, to a method for transmitting a demodulation referencesignal for an uplink data and a device for supporting the same.

BACKGROUND ART

Mobile communication systems have been generally developed to providevoice services while guaranteeing user mobility. Such mobilecommunication systems have gradually expanded their coverage from voiceservices through data services up to high-speed data services. However,as current mobile communication systems suffer resource shortages andusers demand even higher-speed services, development of more advancedmobile communication systems is needed.

The requirements of the next-generation mobile communication system mayinclude supporting huge data traffic, a remarkable increase in thetransfer rate of each user, the accommodation of a significantlyincreased number of connection devices, very low end-to-end latency, andhigh energy efficiency. To this end, various techniques, such as smallcell enhancement, dual connectivity, massive multiple input multipleoutput (MIMO), in-band full duplex, non-orthogonal multiple access(NOMA), supporting super-wide band, and device networking, have beenresearched.

DISCLOSURE Technical Problem

An embodiment of the present disclosure provides a method fortransmitting a demodulation reference signal for an uplink data by usinga low PAPR sequence.

The technical objects of the present disclosure are not limited to theaforementioned technical objects, and other technical objects, which arenot mentioned above, will be apparently appreciated by a person havingordinary skill in the art from the following description.

Technical Solution

In one aspect, there is provided a method of transmitting, by aterminal, a demodulation reference signal (DMRS) for an uplink data in awireless communication system, the method comprising receiving, from abase station, a radio resource control (RRC) signaling including controlinformation representing that transform precoding for an uplink isenabled; generating a low peak to average power ratio (PAPR) sequencebased on a length-6 sequence; generating a sequence used for thedemodulation reference signal based on the low PAPR sequence; andtransmitting, to the base station, the demodulation reference signalbased on the sequence used for the demodulation reference signal,wherein the length-6 sequence has an 8-phase shift keying (PSK) symbolas each element of the sequence.

The length-6 sequence is determined by e^(jφ(i)π/8) and the i is anindex of elements of the length-6 sequence.

A value of the φ(i) comprises (-1 -7 -3 -5 -1 3), (-7 3 -7 5 -7 -3), (5-7 7 1 5 1), (-7 3 1 5 -1 3), (-7 -5 -1 -7 -5 5), (-7 1 -3 3 7 5) and(-7 1 -3 1 5 1).

A sequence which is cyclic shifted for the φ(i) is a same sequence withthe φ(i).

A number of possible value of the φ(i) is 8⁶.

A value of an auto-correlation for the low PAPR sequence is less than aspecific value.

The method further comprises applying a frequency domain spectrumshaping (FDSS) to the low PAPR sequence.

The low PAPR sequence is frequency division multiplexed (FDM) for 2antenna ports as a Comb-2 form.

The low PAPR sequence which is used for each of the 2 antenna ports isdifferent for each other.

In another aspect, there is provided a terminal for transmitting ademodulation reference signal (DMRS) for an uplink data in a wirelesscommunication system, the terminal comprising a transceiver configuredto transmit and receive radio signals; and a processor operativelycoupled to the transceiver, wherein the processor controls to receive,from a base station, a radio resource control (RRC) signaling includingcontrol information representing that transform precoding for an uplinkis enabled; generate a low peak to average power ratio (PAPR) sequencebased on a length-6 sequence; generate a sequence used for thedemodulation reference signal based on the low PAPR sequence; andtransmit, to the base station, the demodulation reference signal basedon the sequence used for the demodulation reference signal, wherein thelength-6 sequence has an 8-phase shift keying (PSK) symbol as eachelement of the sequence.

In another aspect, there is provided an apparatus comprising one or morememories and one or more processors operatively coupled to the one ormore memories, wherein the one or more processors control the apparatusto receive, from a base station, a radio resource control (RRC)signaling including control information representing that transformprecoding for an uplink is enabled; generate a low peak to average powerratio (PAPR) sequence based on a length-6 sequence; generate a sequenceused for the demodulation reference signal based on the low PAPRsequence; and transmit, to the base station, the demodulation referencesignal based on the sequence used for the demodulation reference signal,wherein the length-6 sequence has an 8-phase shift keying (PSK) symbolas each element of the sequence.

In another aspect, there is provided one or more non-transitorycomputer-readable media (CRM) storing one or more instructions, whereinthe one or more instructions executable by the one or more processorsallow a terminal to receive, from a base station, a radio resourcecontrol (RRC) signaling including control information representing thattransform precoding for an uplink is enabled; generate a low peak toaverage power ratio (PAPR) sequence based on a length-6 sequence;generate a sequence used for the demodulation reference signal based onthe low PAPR sequence; and transmit, to the base station, thedemodulation reference signal based on the sequence used for thedemodulation reference signal, wherein the length-6 sequence has an8-phase shift keying (PSK) symbol as each element of the sequence.

Advantageous Effects

According to the present disclosure, there is an effect that PAPRperformance can be enhanced by using a sequence constituted by M-PSKand/or M-QAM symbols.

Effects obtainable in the present disclosure are not limited to theaforementioned effects and other unmentioned effects will be clearlyunderstood by those skilled in the art from the following description.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included as part of the detaileddescription in order to provide a thorough understanding of the presentdisclosure, provide embodiments of the present disclosure and togetherwith the description, describe the technical features of the presentdisclosure.

FIG. 1 is a diagram illustrating one example of an NR systemarchitecture.

FIG. 2 is a diagram illustrating one example of a frame structure in NR.

FIG. 3 illustrates one example of a resource grid in NR.

FIG. 4 is a diagram illustrating one example of a physical resourceblock in NR.

FIG. 5 is a diagram illustrating one example of a 3GPP signaltransmitting and receiving method.

FIG. 6 is a block diagram of a wireless communication system to whichmethods proposed in the present disclosure may be applied.

FIG. 7 illustrates an SSB structure.

FIG. 8 illustrates SSB transmission.

FIG. 9 illustrates that a UE acquires information on DL timesynchronization.

FIG. 10 illustrates a system information (SI) acquisition process.

FIG. 11 illustrates a method for informing SSB (SSB_tx) which isactually transmitted.

FIG. 12 is a diagram illustrating PAPR performance of many sequences fora case where an FDSS filter is used and a case where the FDSS filter isnot used.

FIG. 13 illustrates one example of a system model and/or a procedure fora DFT-s-OFDM based system.

FIG. 14 is a diagram illustrating a flowchart of Method 1 proposed inthe present disclosure.

FIG. 15 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

FIG. 16 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

FIG. 17 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

FIG. 18 illustrates one example for adaptively applying an FDSS filterproposed in the present disclosure.

FIG. 19 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

FIG. 20 is a flowchart illustrating one example of a method forgenerating a low PAPR sequence proposed in the present disclosure.

FIG. 21 illustrates a communication system applied to the presentdisclosure.

FIG. 22 illustrates a wireless device which may be applied to thepresent disclosure.

FIG. 23 illustrates a signal processing circuit applied to the presentdisclosure.

FIG. 24 illustrates another example of a wireless device applied to thepresent disclosure.

FIG. 25 illustrates a portable device applied to the present disclosure.

MODE FOR DISCLOSURE

Hereinafter, downlink (DL) means communication from the base station tothe terminal and uplink (UL) means communication from the terminal tothe base station. In downlink, a transmitter may be part of the basestation, and a receiver may be part of the terminal. In downlink, thetransmitter may be part of the terminal and the receiver may be part ofthe terminal. The base station may be expressed as a first communicationdevice and the terminal may be expressed as a second communicationdevice. A base station (BS) may be replaced with terms including a fixedstation, a Node B, an evolved-NodeB (eNB), a Next Generation NodeB(gNB), a base transceiver system (BTS), an access point (AP), a network(5G network), an AI system, a road side unit (RSU), a robot, and thelike. Further, a ‘terminal’ may be fixed or mobile and may be replacedwith terms including a mobile station (UE), a mobile station (MS), auser terminal (UT), a mobile subscriber station (MSS), a subscriberstation (SS) Advanced Mobile Station (WT), a Wireless Terminal (WT), aMachine-Type Communication (MTC) device, a Machine-to-Machine (M2M)device, and a Device-to-Device (D2D) device, a vehicle, a robot, an AImodule, and the like.

The following technology may be used in various wireless access systemincluding CDMA, FDMA, TDMA, OFDMA, SC-FDMA, and the like. The CDMA maybe implemented as radio technology such as Universal Terrestrial RadioAccess (UTRA) or CDMA2000. The TDMA may be implemented as radiotechnology such as a global system for mobile communications(GSM)/general packet radio service (GPRS)/enhanced data rates for GSMevolution (EDGE). The OFDMA may be implemented as radio technology suchas Institute of Electrical and Electronics Engineers (IEEE) 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Evolved UTRA (E-UTRA), or thelike. The UTRA is a part of Universal Mobile Telecommunications System(UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution(LTE) is a part of Evolved UMTS (E-UMTS) using the E-UTRA andLTE-Advanced (A)/LTE-A pro is an evolved version of the 3GPP LTE. 3GPPNR (New Radio or New Radio Access Technology) is an evolved version ofthe 3GPP LTE/LTE-A/LTE-A pro.

For clarity of description, the technical spirit of the presentdisclosure is described based on the 3GPP communication system (e.g.,LTE-A or NR), but the technical spirit of the present disclosure are notlimited thereto. LTE means technology after 3GPP TS 36.xxx Release 8. Indetail, LTE technology after 3GPP TS 36.xxx Release 10 is referred to asthe LTE-A and LTE technology after 3GPP TS 36.xxx Release 13 is referredto as the LTE-A pro. The 3GPP NR means technology after TS 38.xxxRelease 15. The LTE/NR may be referred to as a 3GPP system. “xxx” meansa standard document detail number. The LTE/NR may be collectivelyreferred to as the 3GPP system. Matters disclosed in a standard documentopened before the present disclosure may be referred to for a backgroundart, terms, abbreviations, etc., used for describing the presentdisclosure. For example, the following documents may be referred to.

3Gpp LTE

-   36.211: Physical channels and modulation-   36.212: Multiplexing and channel coding-   36.213: Physical layer procedures-   36.300: Overall description-   36.331: Radio Resource Control (RRC)

3Gpp NR

-   38.211: Physical channels and modulation-   38.212: Multiplexing and channel coding-   38.213: Physical layer procedures for control-   38.214: Physical layer procedures for data-   38.300: NR and NG-RAN Overall Description-   38.331: Radio Resource Control (RRC) protocol specification

NR Radio Access (NR)

As more and more communication devices require larger communicationcapacity, there is a need for improved mobile broadband communicationcompared to the existing radio access technology (RAT). Further, massivemachine type communications (MTCs), which provide various servicesanytime and anywhere by connecting many devices and objects, are one ofthe major issues to be considered in the next generation communication.In addition, a communication system design considering a service/UEsensitive to reliability and latency is being discussed. Theintroduction of next generation radio access technology consideringenhanced mobile broadband communication (eMBB), massive MTC (mMTC),ultra-reliable and low latency communication (URLLC) is discussed, andin the present disclosure, the technology is called new RAT forconvenience. The NR is an expression representing an example of 5G radioaccess technology (RAT).

In a New RAT system including NR uses an OFDM transmission scheme or asimilar transmission scheme thereto. The new RAT system may follow OFDMparameters different from OFDM parameters of LTE. Alternatively, the newRAT system may follow numerology of conventional LTE/LTE-A as it is orhave a larger system bandwidth (e.g., 100 MHz). Alternatively, one cellmay support a plurality of numerologies. In other words, UEs thatoperate with different numerologies may coexist in one cell.

The numerology corresponds to one subcarrier spacing in a frequencydomain. Different numerology may be defined by scaling referencesubcarrier spacing to an integer N.

System Architecture

FIG. 1 is a diagram illustrating one example of an NR systemarchitecture.

Referring to FIG. 1 , NG-RAN is constituted by an NG-RA user plane (newAS sublayer/PDCP/RLC/MAC/PHY) and gNBs providing a control plane (RRC)protocol termination for a user equipment (UE). The gNBs areinterconnected through an Xn interface. The gNB is also connected to NGCthrough an NG interface. More specifically, the gNB is connected to anAccess and Mobility Management Function (AMF) through an N2 interfaceand a User Plane Function (UPF) through an N3 interface.

Frame Structure

FIG. 2 is a diagram illustrating one example of a frame structure in NR.

The NR system may support multiple numerologies. Here, the numerologymay be defined by a subcarrier spacing and cyclic prefix (CP) overhead.In this case, multiple subcarrier spacings may be derived by scaling abasic subcarrier spacing with an integer N (or µ ). Further, even if itis assumed that a very low subcarrier spacing is not used at a very highcarrier frequency, the used numerology may be selected independently ofa frequency band.

In addition, in the NR systems, various frame structures depending onmultiple numerologies may be supported.

Hereinafter, Orthogonal Frequency Division Multiplexing (OFDM)numerology and the frame structure which may be considered in the NRsystem will be described.

Multiple OFDM numerologies supported in the NR systems may be defined asshown in Table 1.

TABLE 1 µ Δƒ = 2^(µ) · 15 [kHz] Cyclic prefix(CP) 0 15 Normal 1 30Normal 2 60 Normal, Extended 3 120 Normal 4 240 Normal

The NR supports multiple numerologies (or subcarrier spacing (SCS)) forsupporting various 5G services. For example, when the SCS is 15 kHz, awide area in traditional cellular bands is supported and when the SCS is30 kHz/60 kHz, dense-urban, lower latency, and wider carrier bandwidthare supported, and when the SCS is 60 kHz or higher therethan, abandwidth larger than 24.25 GHz is supported in order to overcome phasenoise.

An NR frequency band is defined as frequency ranges of two types (FR1and FR2). FR1 may mean a sub 6-GHz range and FR2 as above 6-GHz rangemay mean millimeter wave (mmW).

Table 2 below shows a definition of an NR frequency band.

TABLE 2 Frequency Range designation Corresponding frequency rangeSubcarrier Spacing FR1 450 MHz - 6000 MHz 15, 30, 60 kHz FR2 24250 MHz -52600 MHz 60, 120, 240 kHz

With respect to the frame structure in the NR system, sizes of variousfields of a time domain is expressed in multiples of a time unit of

T_(s) = 1/(Δf_(max) ⋅ N_(f)).

Here,

Δf_(max) = 480 ⋅ 10³

and

N_(f) = 4096.

Downlink and uplink transmission is configured by a radio frame havingan interval of

T_(f) = (Δf_(max)N_(f)/100)⋅ T_(s) = 10ms.

Here, the radio frame is constituted by 10 subframes each having aninterval of

T_(sf) = (Δf_(max)N_(f)/1000) ⋅ T_(s) = 1 ms.

In this case, there may be one set of frames for uplink and one set offrames for downlink.

Further, transmission of uplink frame number i from the user equipment(UE) should be started earlier than the start of the downlink frame inthe corresponding UE by

T_(TA) = N_(TA)T_(s.)

For numerology µ , slots are numbered in an increasing order of

n₅^(μ) ∈ {0, ..., N_(subframe)^(slots, μ)  − 1}

in the subframe and numbered in an increasing order of

n_(s,f)^(μ) ∈ {0, ..., N_(frame)^(slots, μ)  − 1}

in the radio frame. One slot is constituted by

N_(symb)^(μ)

consecutive OFDM symbols and

N_(symb)^(μ)

is determined according to the used numerology and a slot configuration.A start of slot

n_(s)^(μ)

in the subframe is temporally aligned with the start of OFDM symbol

n_(s)^(μ)N_(symb)^(μ)

in the same subframe.

All UEs may not simultaneously perform transmission and reception andthis means that all OFDM symbols of a downlink slot or an uplink slotmay not be used.

Table 3 shows the number

N_(symb)^(slot)

of OFDM symbols for each slot, the number

N_(slot)^(frame, μ)

of slots for each radio frame, and the number

N_(slot)^(subframe, μ)

of slots for each subframe in a normal CP and Table 4 shows the numberof OFDM symbols for each slot, the number of slots for each radio frame,and the number of slots for each subframe in an extended CP.

TABLE 3 µ N_(symb)^(slot) N_(slot)^(frame, μ) N_(slot)^(subframe, μ) 014 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

TABLE 4 µ N_(symb)^(slot) N_(slot)^(frame, μ) N_(slot)^(subframe, μ) 212 40 4

FIG. 2 illustrates one example of a case where µ = 2 and referring toTable 3, 1 subframe may include 4 slots. 1 subframe = {1, 2, 4} slotsillustrated in FIG. 2 is one example and the number of slots which maybe included in 1 subframe is defined as shown in Table 3 or 4.

Further, mini-slot may include 2, 4, or 7 symbols or may include moresymbols or less symbols therethan.

Physical Resource

With respect to the physical resource in the NR system, an antenna port,a resource grid, a resource element, a resource block, a carrier part,and the like may be considered.

Hereinafter, the physical resources which may be considered in the NRsystem will be described in detail.

First, with respect to the antenna port, the antenna port is defined sothat a channel in which the symbol on the antenna port is transportedmay be inferred from a channel in which different symbols on the sameantenna port are transported. When a large-scale property of a channelin which a symbol on one antenna port is transported may be interredfrom a channel in which symbols on different antenna ports aretransported, two antenna ports may have a quasi co-located or quasico-location (QC/QCL) relationship. Here, the large-scale propertyincludes at least one of a delay spread, a Doppler spread, a frequencyshift, average received power, and a received timing.

FIG. 3 illustrates one example of a resource grid in NR.

Referring to FIG. 3 , it is exemplarily described that the resource gridis constituted by

N_(RB)^(μ)N_(5C)^(RB)

subcarriers on the frequency domain and one subframe is constituted by14 ·2 µ OFDM symbols, but the present disclosure is not limited thereto.

In the NR system, a transmitted signal is described by one or moreresource grids constituted by

N_(RB)^(μ)N_(sc)^(RB)

subcarriers and

2^(μ)N_(symb)^((μ))

OFDM symbols. Here,

N_(RB)^(μ) ≤ N_(RB)^(max, μ).

. The

N_(RB)^(max, μ)

represents a maximum transmission bandwidth and this may vary betweenuplink and downlink in addition to numerologies.

In this case, as illustrated in FIG. 2 , one resource grid may beconfigured for each numerology µ and antenna port p.

Each resource element of the resource grid for the numerology µ and theantenna port p is referred to as the resource element and uniquelyidentified by an index pair(k,l). Here,

k = 0, ..., N_(RB)^(μ)N_(sc)^(RB) − 1

represents an index on the frequency domain and

$\overline{l} = 0,...,2^{\mu}N_{\text{symb}}^{(\mu)} - 1$

refers to the position of the symbol in the subframe. When the resourceelement in the slot is referred to, the index pair (k,l) is used. Here,

l = 0, ..., N_(symb)^(μ) − 1.

A resource element for the numerology µ and the antenna port pcorresponds to a complex value

$a_{k,\overline{l}}^{({p,\mu})}.$

When there is no risk of confusion or when a specific antenna port ornumerology is not specified, the indexes p and µ may be dropped, and asa result, the complex value may be

$a_{k,\overline{l}}^{(p)}$

or

$a_{k,\overline{l}}.$

Further, the resource block (RB) is defined

N_(5C)^(RB) = 12

consecutive subcarriers on the frequency domain.

Point A serves as a common reference point of a resource block grid andis acquired as follows.

-   OffsetToPointA for PCell downlink indicates the frequency offset    between the lowest subcarrier of the lowest resource block    overlapping the SS/PBCH block used by the UE for initial cell    selection and point A and is expressed by resource block units    assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHz subcarrier    spacing for FR2; and-   absoluteFrequencyPointA indicates the frequency-position of point A    expressed as in an absolute radio-frequency channel number (ARFCN).

Common resource blocks are numbered upward from 0 in the frequencydomain for a subcarrier spacing configuration µ.

A center of subcarrier 0 common resource block 0 for the subcarrierspacing configuration µ coincides with ‘point A’. A resource element(k,l) for the common resource block number

n_(CRB)^(μ)

and the subcarrier spacing configuration µ in the frequency domain isgiven as shown in Equation 1 below.

$n_{\text{CRB}}^{\mu} = \left\lbrack \frac{k}{N_{\text{sc}}^{\text{RB}}} \right\rbrack$

Here, k is relatively defined at point A so that k = 0 to correspond tothe subcarrier centering point A. Physical resource blocks are numberedfrom 0 to

N_(BWP,i)^(size) − 1

within a bandwidth part (BWP) and i represents the number of the BWP. Arelationship between physical resource block n_(PRB) and common resourcebock n_(CRB) is given by Equation D2 below.

n_(CRB) = n_(PRB) + N_(BWP,i)^(start)

Here,

N_(BWP,i)^(start)

represents a common resource block in which the BWP relatively starts tocommon resource block 0.

Bandwidth Part (BWP)

The NR system may support up to 400 MHz per component carrier (CC). If aUE which operates in wideband CC operates while continuously turning onRF for all CCs, UE battery consumption may increase. Alternatively, whenseveral use cases (e.g., eMBB, URLLC, Mmtc, V2X, etc.) which operate inone wideband CC are considered, different numerologies (e.g.,sub-carrier spacing) may be supported for each frequency band in thecorresponding CC. Alternatively, a capability for the maximum bandwidthmay vary for each UE. By considering this, the eNB may instruct the UEto operate only in a partial bandwidth rather than the entire bandwidthof the wideband CC and the corresponding partial bandwidth is defined asthe bandwidth part (BWP) for convenience. The BWP may be constituted byconsecutive resource blocks (RBs) on the frequency axis and maycorrespond to one numerology (e.g., sub-carrier spacing, CP length,slot/mini-slot duration).

Meanwhile, the eNB may configure multiple BWPs even in one CC configuredto the UE. As one example, a BWP occupying a relatively small frequencydomain may be configured in a PDCCH monitoring slot and PDSCH indicatedin PDCCH may be scheduled onto a BWP larger therethan. Alternatively,when UEs are concentrated on a specific BWP, some UEs may be configuredto other BWPs for load balancing. Alternatively, a partial spectrum ofthe entire bandwidth may be excluded both BWPs may be configured even inthe same slot by considering frequency domain inter-cell interferencecancellation between neighboring cells. In other words, the eNB mayconfigure at least one DL/UL BWP to the UE associated with the widebandCC and activate at least one DL/UL BWP (by L1 signaling or MAC CE or RRCsignaling) among configured DL/UL BWP(s) at a specific time andswitching may be indicated to another configured DL/UL BWP (by L1signaling or MAC CE or RRC signaling) or when a timer value is expiredbased on a timer, the timer value may be switched to the DL/UL BWP. Inthis case, the activated DL/UL BWP is defined as an active DL/UL BWP.However, in a situation in which the UE is in an initial access processor before RRC connection is set up, the UE may not receive aconfiguration for the DL/UL BWP and in such a situation, the DL/UL BWPassumed by the UE is defined as an initial active DL/UL BWP.

3GPP Signal Transmitting and Receiving Method

FIG. 5 is a diagram illustrating one example of a 3GPP signaltransmitting and receiving method.

Referring to FIG. 5 , when the UE is powered on or newly enters a cell,the UE performs an initial cell search operation such as synchronizingwith the eNB (S201). To this end, the UE may receive a PrimarySynchronization Channel (P-SCH) and a Secondary Synchronization Channel(S-SCH) from the eNB and synchronize with the eNB and acquireinformation such as a cell ID or the like. Thereafter, the UE mayreceive a Physical Broadcast Channel (PBCH) from the eNB and acquirein-cell broadcast information. Meanwhile, the UE receives a DownlinkReference Signal (DL RS) in an initial cell search step to check adownlink channel status.

A UE that completes the initial cell search receives a Physical DownlinkControl Channel (PDCCH) and a Physical Downlink Control Channel (PDSCH)according to information loaded on the PDCCH to acquire more specificsystem information (S202).

Meanwhile, when there is no radio resource first accessing the eNB orfor signal transmission, the UE may perform a Random Access Procedure(RACH) to the eNB (S203 to S206). To this end, the UE may transmit aspecific sequence to a preamble through a Physical Random Access Channel(PRACH) (S203 and S205) and receive a response message for the preamblethrough the PDCCH and a corresponding PDSCH (S204 and S206). In the caseof a contention based RACH, a Contention Resolution Procedure may beadditionally performed.

The UE that performs the above procedure may then perform PDCCH/PDSCHreception (S207) and Physical Uplink Shared Channel (PUSCH)/PhysicalUplink Control Channel (PUCCH) transmission (S208) as a generaluplink/downlink signal transmission procedure. In particular, the UEreceives Downlink Control information (DCI) through the PDCCH. Here, theDCI may include control information such as resource allocationinformation for the UE and formats may be different from each otheraccording to a use purpose.

Meanwhile, the control information which the UE transmits to the eNBthrough the uplink or the UE receives from the eNB includes adownlink/uplink ACK/NACK signal, a Channel Quality Indicator (CQI), aPrecoding Matrix Index (PMI), a Rank Indicator (RI), and the like. Inthe case of the 3GPP LTE system, the UE may transmit the controlinformation such as the CQI/PMI/RI, etc., through the PUSCH and/orPUCCH.

Table 5 shows one example of a DCI format in the NR system.

TABLE 5 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell

Referring to Table 5, DCI format 0_0 is used for scheduling of the PUSCHin one cell.

Information included in DCI format 0_0 is CRC-scrambled and transmittedby C-RNTI, CS-RNTI, or MCS-C-RNTI. In addition, DCI format 0_1 is usedfor reserving the PUSCH in one cell. Information included in DCI format0_1 is CRC-scrambled and transmitted by C-RNTI, CS-RNTI, SP-CSI-RNTI, orMCS-C-RNTI. DCI format 1_0 is sued for scheduling of the PDSCH in one DLcell. Information included in DCI format 1_0 is CRC-scrambled andtransmitted by C-RNTI, CS-RNTI, or MCS-C-RNTI. DCI format 1_1 is suedfor scheduling of the PDSCH in one cell. Information included in DCIformat 1_1 is CRC-scrambled and transmitted by C-RNTI, CS-RNTI, orMCS-C-RNTI. DCI format 2_1 is used to inform PRB(s) and OFDM symbol(s)of which the UE may assume not intending transmission.

The following information included in DCI format 2_1 is CRC-scrambledand transmitted by INT-RNTI.

-   preemption indication 1, preemption indication 2, ..., preemption    indication N.

Block Diagram of Wireless Communication System

FIG. 6 is a block diagram of a wireless communication system to whichmethods proposed in the present disclosure may be applied.

Referring to FIG. 6 , a wireless communication system includes a firstcommunication device 910 and/or a second communication device 920. Theexpression of ‘A and/or B’ may be construed as the same meaning asIncluding at least one of A and B’. The first communication device mayindicate the eNB and the second communication device may indicate the UE(or the first communication device may indicate the UE and the secondcommunication device may indicate the eNB).

A base station (BS) may be replaced with terms including a fixedstation, a Node B, an evolved-NodeB (eNB), a Next Generation NodeB(gNB), a base transceiver system (BTS), an access point (AP), general NB(gNB), a 5G system, a network, an Al system, a road side unit (RSU), arobot, and the like. Further, a ‘terminal’ may be fixed or mobile andmay be replaced with terms including a mobile station (UE), a mobilestation (MS), a user terminal (UT), a mobile subscriber station (MSS), asubscriber station (SS) Advanced Mobile Station (WT), a WirelessTerminal (WT), a Machine-Type Communication (MTC) device, aMachine-to-Machine (M2M) device, and a Device-to-Device (D2D) device, avehicle, a robot, an Al module, and the like.

The first communication device and the second communication deviceinclude processors 911 and 921, memories 914 and 924, one or more Tx/Rxradio frequency (RF) modules 915 and 925, Tx processors 912 and 922, Rxprocessors 913 and 923, and antennas 916 and 926. The processorimplements a function, a process, and/or a method which are describedabove. More specifically, a higher layer packet from a core network isprovided to the processor 911 in DL (communication from the firstcommunication device to the second communication device). The processorimplements a function of an L2 layer. In the DL, the processor providesmultiplexing between a logical channel and a transmission channel andallocation of radio resources to the second communication device 920 andtakes charge of signaling to the second communication device. Thetransmit (TX) processor 912 implement various signal processingfunctions for an L1 layer (i.e., physical layer). The signal processingfunctions facilitate forward error correction (FEC) at the secondcommunication device and include coding and interleaving. Encoded andmodulated symbols are divided into parallel streams, each stream ismapped to an OFDM subcarrier, multiplexed with a reference signal (RS)in a time and/or frequency domain, and combined together by usinginverse fast Fourier transform (IFFT) to create a physical channelcarrying a time domain OFDMA symbol stream. An OFDM stream is spatiallyprecoded in order to create multiple spatial streams. Respective spatialstreams may be provided to different antennas 916 via individual Tx/Rxmodules (or transceivers, 915). Each Tx/Rx module may modulate an RFcarrier into each spatial stream for transmission. In the secondcommunication device, each Tx/Rx module (or transceiver, 925) receives asignal through each antenna 926 of each Tx/Rx module. Each Tx/Rx modulereconstructs information modulated with the RF carrier and provides thereconstructed information to the receive (RX) processor 923. The RXprocessor implements various signal processing functions of layer 1. TheRX processor may perform spatial processing on information in order toreconstruct an arbitrary spatial stream which is directed for the secondcommunication device. When multiple spatial streams are directed to thesecond communication device, the multiple spatial streams may becombined into a single OFDMA symbol stream by multiple RX processors.The RX processor transforms the OFDMA symbol stream from the time domainto the frequency domain by using fast Fourier transform (FFT). Afrequency domain signal includes individual OFDMA symbol streams forrespective subcarriers of the OFDM signal. Symbols on the respectivesubcarriers and the reference signal are reconstructed and demodulatedby determining most likely signal arrangement points transmitted by thefirst communication device. The soft decisions may be based on channelestimation values. The soft decisions are decoded and deinterleaved toreconstruct data and control signals originally transmitted by the firstcommunication device on the physical channel. The corresponding data andcontrol signals are provided to the processor 921.

UL (communication from the second communication device to the firstcommunication device) is processed by the first communication device 910in a scheme similar to a description of a receiver function in thesecond communication device 920. Each Tx/Rx module 925 receives thesignal through each antenna 926. Each Tx/Rx module provides the RFcarrier and information to the RX processor 923. The processor 921 maybe associated with the memory 924 storing a program code and data. Thememory may be referred to as a computer readable medium.

Abbreviation and Definition

-   PUSCH: Physical Uplink Shared Channel-   PUCCH: Physical Uplink Control Channel-   FDSS: Frequency Domain Spectrum Shaping-   PSK: Phase Shift Keying-   QAM: Quadrature Amplitude Modulation-   PAPR: Peak-to-Average Power Ratio-   DMRS: DeModulation Reference Signals-   ACK: Acknowledgement-   NACK: Negative Acknowledgement-   CA: Carrier aggregation-   DCI: Downlink Control format Indicator/index-   MAC-CE: Multiple Access Channel Control Elements-   BWP: Bandwidth part-   RF: Radio frequency-   CC: Component carrier-   SS: Synchronization Signals-   SSB: Synchronization signal block - The SSB is regarded to be the    same as the SS/PBCH block in the present disclosure.-   SSBRI: SSB resource index/indicator-   IM: Interference measurement-   FDM: Frequency division multiplexing-   TDM: Time division multiplexing-   RS: Reference Signal(s)-   CSI-RS or CSIRS: Channel State Information Reference Signals-   CSI-IM: Channel State Information Interference Measurement-   CRI: CSI-RS resource index/indicator-   DM-RS or DMRS: Demodulation Reference Signals-   MAC: Medium Access Control-   MAC-CE: Medium Access Control Channel Element-   NZP: Non Zero Power-   ZP: Zero power-   PT-RS or PTRS: Phase Tracking Reference Signals-   SRS: Sounding Reference Signals-   SRI: SRS resource index/indicator-   PRS: Positioning Reference Signals-   PRI: PRS resource index/indicator-   OFDM: Orthogonal Frequency Division Multiplexing-   TX: Transmitter-   TP: Transmission Point-   BS: Base station-   RX: Receiver-   RRC: Radio Resource Control-   RSRP: Reference Signal Received Power-   RSRQ: Reference Signal Received Quality-   SNR: Signal to Noise Ratio-   SINR: Signal to Interference plus Noise Ratio-   URLLC: Ultra Reliable Low Latency Communication-   PUSCH: Physical Uplink Shared Channels-   PUCCH: Physical Uplink Control Channels-   PDCCH: Physical Downlink Control Channels-   PDSCH: Physical Downlink Shared Channels-   ID: Identity (or meaning identity/identification number)-   UL: Uplink-   DL: Downlink-   UE: User equipment (meaning the UE)-   gNB: generic NodeB (similar concept to the eNB)

Initial Access (IA) Procedure Synchronization Signal Block (SSB)Transmission and Related Operation

FIG. 7 illustrates an SSB structure. The UE may perform cell search,system information acquisition, beam alignment for initial access, DLmeasurement, etc., based on an SSB. The SSB is mixedly used with anSS/Synchronization Signal/Physical Broadcast channel (PBCH) block.

Referring to FIG. 7 , the SSB is constituted by PSS, SSS, and PBCH. TheSSB is constituted by four continuous OFDM symbols and the PSS, thePBCH, the SSS/PBCH, and the PBCH are transmitted for each OFDM symbol.Each of the PSS and the SSS may be constituted by one OFDM symbol and127 subcarriers and the PBCH is constituted by 3 OFDM symbols and 576subcarriers. Polar coding and quadrature phase shift keying (QPSK) areapplied to the PBCH. The PBCH is constituted by a data RE and ademodulation reference signal (DMRS) RE for each OFDM symbol. Three DMRSREs exist for each RB, and three data REs exist between DMRS REs.

Cell Search

The cell search refers to a process of acquiring time/frequencysynchronization of the cell and detecting a cell identifier (ID) (e.g.,physical layer cell ID (PCID)) of the cell by the UE. The PSS is used todetect the cell ID within a cell ID group and the SSS is used to detectthe cell ID group. The PBCH is used for SSB (time) index detection andhalf-frame detection.

A cell search process of the UE may be organized as shown in Table 6below.

TABLE 6 Type of Signals Operations 1st Step PSS SS/PBCH block (SSB)symbol timing acquisition Cell ID detection within a cell ID group (3hypothesis) 2nd Step SSS Cell ID group detection (336 hypothesis) 3rdStep PBCH DMRS SSB index and Half frame (HF) index (Slot and frameboundary detection) 4th Step PBCH Time information (80 ms, System FrameNumber (SFN), SSB index, HF) Remaining Minimum System Information (RMSI)Control resource set (CORESET)/Search space configuration 5th Step PDCCHand PDSCH Cell access information RACH configuration

There are 336 cell ID groups, and three cell IDs exist for each cell IDgroup. There may be a total of 1008 cell IDs and the cell ID may bedefined by Equation 3.

N_(ID)^(cell) = 3N_(ID)⁽¹⁾ + N_(ID)⁽²⁾

Here,

N_(ID)⁽¹⁾ ∈ {0, 1, ..., 335}andN_(ID)⁽²⁾ ∈ {0, 1, 2} .

Here, NcellID represents a cell ID (e.g., PCID). N(1)ID represents acell ID group and is provided/acquired through the SSS. N(2)IDrepresents a cell ID in the cell ID group and is provided/acquiredthrough the PSS.

PSS sequence dPSS(n) may be defined to satisfy Equation 4.

$\begin{array}{l}{d_{\text{PSS}}(n) = 1 - 2x(m)} \\{\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu} m = \left( {n + 43N_{\text{ID}}^{(2)}} \right){mod}127} \\{\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu} 0 \leq n < 127}\end{array}$

Here, x(i + 7) = (x(i + 4)+ x(i))mod 2, and

[x(6)  x(5)  x(4)  x(3)  x(2)  x(1)  x(0)] = [1  1  1  0  1  1  0],

SSS sequence dSSS(n) may be defined to satisfy Equation 5.

d_(SSS)(n) = [1 − 2x₀((n + m₀)mod127)][1 − 2x₁((n + m₁)mod127)]

$m_{0} = 15\left\lfloor \frac{N_{\text{ID}}^{(1)}}{112} \right\rfloor + 5N_{\text{ID}}^{(2)}$

$\begin{array}{l}{m_{1} = N_{\text{ID}}^{(1)}{mod}112} \\{\mspace{6mu}\mspace{6mu}\mspace{6mu} 0 \leq n < 127}\end{array}$

x₀(i + 7) = (x₀(i + 4) + x₀(i))mod2

Here,  x₁(i + 7) = (x₁(i + 1) + x₁(i))mod2 ,and

$\begin{array}{r}{\left\lbrack {x_{0}(6)\mspace{6mu}\mspace{6mu} x_{0}(5)\mspace{6mu}\mspace{6mu} x_{0}(4)\mspace{6mu}\mspace{6mu} x_{0}(3)\mspace{6mu}\mspace{6mu} x_{0}(2)\mspace{6mu}\mspace{6mu} x_{0}(1)\mspace{6mu}\mspace{6mu} x_{0}(0)} \right\rbrack = \left\lbrack {0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1} \right\rbrack} \\{\left\lbrack {x_{1}(6)\mspace{6mu}\mspace{6mu} x_{1}(5)\mspace{6mu}\mspace{6mu} x_{1}(4)\mspace{6mu}\mspace{6mu} x_{1}(3)\mspace{6mu}\mspace{6mu} x_{1}(2)\mspace{6mu}\mspace{6mu} x_{1}(1)\mspace{6mu}\mspace{6mu} x_{1}(0)} \right\rbrack = \left\lbrack {0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1} \right\rbrack}\end{array}$

FIG. 8 illustrates SSB transmission.

The SSB is periodically transmitted according to SSB periodicity. An SSBbasic periodicity assumed by the UE in initial cell search is defined as20 ms. After cell access, the SSB periodicity may be configured by oneof {5ms, 10 ms, 20 ms, 40 ms, 80 ms, 160 ms} by the network (e.g., eNB).At a beginning part of the SSB periodicity, a set of SSB bursts isconfigured. The SSB burst set may be configured by a 5-ms time window(i.e., half-frame) and the SSB may be transmitted up to L times withinthe SS burst set. L which is the maximum number of transmissions of theSSB may be given as follows according to a frequency band of a carrier.One slot includes up to two SSBs.

-   For frequency range up to 3 GHz, L = 4-   For frequency range from 3 GHz to 6 GHz, L = 8-   For frequency range from 6 GHz to 52.6 GHz, L = 64

A time position of an SSB candidate in the SS burst set may be definedas follows according to SCS. The time positions of the SSB candidatesare indexed from 0 to L -1 in chronological order within the SSB burstset (i.e., half-frame).

-   Case A - 15 kHz SCS: An index of a start symbol of the candidate SSB    is given as {2, 8} + 14* n. When a carrier frequency is 3 GHz or    less, n = 0, 1. When the carrier frequency is 3 to 6 GHz or less, n    = 0, 1, 2, 3.-   Case B - 30 kHz SCS: The index of the start symbol of the candidate    SSB is given as {4, 8, 16, 20} + 28 * n. When the carrier frequency    is 3 GHz or less, n = 0. When the carrier frequency is 3 to 6 GHz, n    = 0, 1.-   Case C — 30 kHz SCS: The index of the start symbol of the candidate    SSB is given as {2, 8} + 14 * n. When the carrier frequency is 3 GHz    or less, n = 0, 1. When the carrier frequency is 3 to 6 GHz or less,    n = 0, 1, 2, 3.-   Case D - 120 kHz SCS: The index of the start symbol of the candidate    SSB is given as {4, 8, 16, 20} + 28 * n. When the carrier frequency    is more than 6 GHz, n=0, 1,2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16,    17, 18.-   Case E - 240 kHz SCS: The index of the start symbol of the candidate    SSB is given as {8, 12, 16, 20, 32, 36, 40, 44} + 56 * n. When the    carrier frequency is more than 6 GHz, n = 0, 1, 2, 3, 5, 6, 7, 8.

FIG. 9 illustrates that a UE acquires information on DL timesynchronization.

The UE may acquire DL synchronization by detecting the SSB. The UE mayidentify the structure of the SSB burst set based on the detected SSBindex, and thus detect a symbol/slot/half-frame boundary. The number ofthe frame/half-frame to which the detected SSB belongs may be identifiedusing SFN information and half-frame indication information.

Specifically, the UE may acquire 10-bit System Frame Number (SFN)information from the PBCH (s0 to s9). 6 bits of the 10-bit SFNinformation are obtained from a Master information Block (MIB), and theremaining 4 bits are obtained from a PBCH Transport Block (TB).

Next, the UE may acquire 1-bit half-frame indication information (c0).When a carrier frequency is 3 GHz or less, the half-frame indicationinformation may be implicitly signaled using PBCH DMRS. The PBCH DMRSindicates 3-bit information by using one of eight PBCH DMRS sequences.Accordingly, in the case of L = 4, 1 bit which remains after indicatingthe SSB index among 3 bits which may be indicated by using eight PBCHDRMS sequences may be used for half frame indication.

Last, the UE may acquire the SSB index based on a DMRS sequence and aPBCH payload. SSB candidates are indexed from 0 to L-1 in chronologicalorder within the SSB burst set (i.e., half-frame). In the case of L = 8or 64, Least Significant Bit (LSB) 3 bits of the SSB index may beindicated using eight different PBCH DMRS sequences (b0 to b2). In thecase of L = 64, Most Significant Bit (MSB) 3 bits of the SSB index areindicated through the PBCH (b3 to b5). In the case of L = 2, LSB 2 bitsof the SSB index may be indicated using four different PBCH DMRSsequences (b0 and b1). In the case of L = 4, 3 bits which remain afterindicating the SSB index among 3 bits which may be indicated by usingeight PBCH DRMS sequences may be used for the half frame indication(b2).

System Information Acquisition

FIG. 10 illustrates a system information (SI) acquisition process. TheUE may acquire AS-/NAS-information through an SI acquisition process.The SI acquisition process may be applied to UEs which are in anRRC_IDLE state, an RRC_INACTIVE state, an RRC_CONNECTED state.

The SI is divided into a master information block (MIB) and a pluralityof system information blocks (SIB). SI other than the MIB may bereferred to as Remaining Minimum System Information (RSI). The followingmay be referred to for details.

-   The MIB includes information/parameters related to    SystemInformationBlock1 (SIB1) reception and is transmitted through    the PBCH of the SSB. In initial cell selection, the UE assumes that    the half frame with the SSB is repeated with a periodicity of 20 ms.    The UE may check whether a Control Resource Set (CORESET) for a    Type0-PDCCH common search space exists based on the MIB. The    Type0-PDCCH common search space is a kind of PDCCH search space and    is used to transmit a PDCCH for scheduling an SI message. If there    is the Type0-PDCCH common search space, the UE may (i) a plurality    of continuous RBs and one or more continuous symbols constituting    the CORESET and (ii) a PDCCH occasion (i.e., a time domain location    for receiving the PDCCH) based on information (e.g.,    pdcch-ConfigSIB1) in the MIB. If there is no Type0-PDCCH common    search space, pdcch-ConfigSIB1 provides information on a frequency    location where SSB/SIB1 exists and a frequency range where the    SSB/SIB1 does not exist.-   The SIB1 contains information related to the availability and    scheduling (e.g., transmission periodicity, SI-window size) of the    remaining SIBs (hereinafter, referred to as SIBx, x is an integer of    2 or more). For example, the SIB1 may inform whether the SIBx is    periodically broadcasted or whether the SIBx is provided by a    request of the UE according to an on-demand scheme. When the SIBx is    provided by the on-demand scheme, the SIB1 may include information    which the UE requires for performing an SI request. The SIB1 is    transmitted through the PDSCH, the PDCCH for scheduling the SIB1 is    transmitted through the Type0-PDCCH common search space, and the    SIB1 is transmitted through the PDSCH indicated by the PDCCH.-   The SIBx is included in the SI message and transmitted through the    PDSCH. Each SI message is transmitted within a time window (i.e.,    SI-window) which periodically occurs.

Channel Measurement and Rate-Matching

FIG. 11 illustrates a method for informing SSB (SSB_tx) which isactually transmitted.

In the SSB burst set, up to L SSBs may be transmitted and thenumbers/positions of SSB which are actually transmitted may vary foreach eNB/cell. The number/positions of SSBs which are actuallytransmitted are used for rate-matching and measurement and informationon the actually transmitted SSB is indicated as follows.

— In case related to rate-matching: The information may be indicatedthrough UE-specific RRC signaling or RMSI. The UE-specific RRC signalingincludes a full (e.g., length L) bitmap in both below 6 GHz and above 6GHz frequency ranges. Meanwhile, the RMSI includes the full bitmap below6 GHz and a compression type bitmap as illustrated in FIG. 11 above 6GHz. Specifically, the information on the actually transmitted SSB maybe indicated by using group-bitmap (8 bits) + in-group bitmap (8 bits).Herein, a resource (e.g., RE) indicated through the UE-specific RRCsignaling or RMSI may be reserved for SSB transmission and thePDSCH/PUSCH may be rate-matched by considering SSB resources.

-   In case related to measurement: When the network is in an RRC    connected mode, the network (e.g., eNB) may indicate an SSB set to    be measured in a measurement interval. The SSB set may be indicated    for each frequency layer. When there is no indication for the SSB    set, a default SSB set is used. The default SSB set includes all    SSBs in the measurement interval. The SSB set may be indicated by    using the full (e.g., length L) bitmap of the RRC signaling. When    the network is in an RRC idle, the default SSB set is used.

The contents (NR system, frame structure, etc.) described above may beapplied in combination with methods proposed in the present disclosureto be described below or may be supplemented to clarify technicalfeatures of the methods proposed in the present disclosure.

The expression of ‘A/B’ used in the present disclosure may be construedas the same meaning as A and/or B and at least one of A or B.

Several sequences having a specific length may be predefined. This maybe used for transmission of uplink and/or downlink data signal/controlsignal/reference signal. The predefined sequence may be defined (ordetermined) according to several criteria including Peak-to-AveragePower Ratio (PAPR) characteristics, auto-correlation characteristics,and the like.

The present disclosure proposes a method for designing a length-N (thelength of the sequence is N) in which each element of the sequence isconstituted by symbols such as M-Phase Shift Keying (PSK), M-QuadratureAmplitude Modulation (QAM), etc.

When a Frequency Domain Spectrum Shaping (FDSS) filter is used, it isgenerally known that the PAPR performance is enhanced. As an exampletherefor, FIG. 7 may be illustrated. For this reason, schemes areproposed, which consider the FDSS filter together in order to design asequence constituted by pi/2 BPSK modulation symbols and a sequenceconstituted by M-PSK symbols.

FIG. 12 is a diagram illustrating PAPR performance of many sequences fora case where an FDSS filter is used and a case where the FDSS filter isnot used.

In FIG. 12 , the FDSS filter corresponds to a time domain response of[0.28 1 0.28]. Here, [0.28 1 0.28] indicates that a side of a highcenter filter is cut off in the frequency domain.

In FIG. 12 , reference numeral 710 represents PAPR performance of asequence using FDSS and reference numeral 720 represents PAPRperformance of a sequence not using the FDSS.

When PAPR performance for a large number of sequences is viewed, it canbe seen that the PAPR performance is enhanced in the case of using theFDSS filter.

For example, the FDSS corresponds to a time domain response of [0.28,0.28, 1.00].

However, when the PAPR performance is viewed from the viewpoint of aspecific one sequence, an optimal FDSS filter for minimizing the PAPRmay vary for each sequence. However, when a different filter is used foreach sequence, problems such as computation complexity and/orunnecessary implementation complexity of the eNB and the UE may occur.Further, the used filter may vary depending on UE and eNB implementationand the FDSS may not be used due to an increase in complexity or anincrease in block error rate (BLER) depending on the use of the FDSS.

Accordingly, the present disclosure proposes a method for configuring(or defining) a sequence set by considering both a case of using theFDSS filter and a case of not using the FDSS filter when a length-Nsequence set constituted by M-PSK or M-QAM symbols is configured (ordefined or used).

Hereinafter, methods (or proposals) proposed in the present disclosuremay be applied to waveform (CP-OFDM (or transform precoding disabled)and DFT-s-OFDM (transform precoding enabled)) used for DL transmissionand/or UL transmission, respectively. In this regard, the UE mayreceive, from the eNB, information on a waveform to which the followingproposed methods are to be applied through the RRC signaling.

In other words, the RRC signaling may include information on a type ofwaveform to be used for the DL transmission and/or UL transmission. Inaddition, the RRC signaling may be a configuration IE form of areference signal (RS) to which a sequence generating method proposedbelow may be applied.

When the information indicating the type of waveform is included as theRS configuration IE form, the information may include fields (orparameters or information) shown in tables below.

Table 7 shows one example of a case where CP-OFDM is applied.

TABLE 7 transformPrecodingdisabled RS related parameters for CP-OFDM

Table 8 shows one example of a case where DFT-s-OFDM is applied.

TABLE 8 transformPrecodingEnabled RS related parameters for DFT-s-OFDM

The transform precoding may be used as an expression such as transformerprecoder.

Further, equations and values related to pseudo-random sequence(c(i))described below may be used for generation of the sequence anddetermination of an initialization value of the sequence proposed below.

Normal pseudo-random sequences are defined by a length-31 gold sequence.An output sequence c(n) having a length of ^(M)PN is defined by Equation3 below. Here, n=0,1,...,M_(PN)-1.

$\begin{array}{l}{\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu} c(n) = \left( {x_{1}\left( {n + N_{C}} \right) + x_{2}\left( {n + N_{C}} \right)} \right){mod}2} \\{x_{1}\left( {n + 31} \right) = \left( {x_{1}\left( {n + 3} \right) + x_{1}(n)} \right){mod}2} \\{x_{2}\left( {n + 31} \right) = \left( {x_{2}\left( {n + 3} \right) + x_{2}\left( {n + 2} \right) + x_{2}\left( {n + 1} \right) + x_{2}(n)} \right){mod}2}\end{array}$

Here, N_(c) = 1600 and a first m-sequence x₁(n) will be initialized to

x₁(0) = 1, x₁(n) = 0, n = 1, 2, ..., 30

Initialization of a second m-sequence x₂(n) is described by

$c_{\text{init}} = {\sum_{i = 0}^{30}{x_{2}(i) \cdot 2^{i}}}$

having a value depending on application of the sequence.

Method 1

K (>0) sequences (a set of K sequences) in which the length of thesequence is N (> 0) and each element of the sequence is constituted byM-QAM symbols may be designed (or generated or defined) according to arule (or condition) presented below. Here, since the sequence has alength of N, the total number of sequences which may be considered isM^(N). In other words, it may be regarded that a rule (or condition) ofselecting (or choosing) a total of K(K≤M⁸) sequences among a total ofM^(N) available sequences is proposed.

① Among a total of M^(N) sequences, K sequences may be chosen (ordetermined) to have a cross-correlation characteristic of a specificthreshold or a specific level or less with each other.

② Among a total of M^(N) sequences, K sequences having a low autocorrelation characteristic of a specific threshold or a specific levelor less with each other may be chosen (or determined). Theauto-correlation value may be for a specific correlation lag and Ksequences may be chosen (or determined) by considering a threshold foran auto-correlation value for one or more correlation lags.

③ Among a total of M^(N) sequences, K sequences having a low cyclicshift auto-correlation characteristic of a specific threshold orspecific level or less may be chosen (or determined). As a more specificexample, K sequences may be chosen in which a correlation between cyclicshift and not cyclic shift of +L, +L-1, + L-2, ..., -L+1, and/or -Lelements in the length-N sequence is low. The L is equal to or smallerthan N - 1.

In other words, when an n-th specific sequence is defined as x₂(n),sequences in which a value of Equation 7 below is small may be chosen.

${\sum\limits_{0\mspace{6mu} and\mspace{6mu} 11\mspace{6mu}}{x_{11}(n)x_{a}^{}\left( {\left( {n + d} \right){mod}N} \right).}}\mspace{6mu}\mspace{6mu}\text{where d}\,\text{=}\, - \text{L,} - \text{L+1,}...\text{,L} - 1,\text{L}$

④ Among K chosen sequences, all available cyclic shifted forms of aspecific length-N sequence may be regarded as the same sequence.Accordingly, among K chosen sequences, no specific sequence is the sameas an available cyclic shifted form of another sequence.

⑤ Among a total of M^(N) sequences, when a specific FDSS filter isapplied to K sequences, the sequence may be chosen (or determined ordefined) so as to show a low PAPR characteristic of a specific thresholdor specific level (e.g., X (> 0) dB) or less.

For example, the FDSS filter may be an FDSS filter corresponding to thetime domain response [0.28 1 0.28].

Additionally, it may be considered that two or more multiple FDSSfilters are used. Since the PAPR performance shown when applying eachFDSS filter varies depending on the specific sequence, multiple FDSSfilters may be used by considering that the PAPR performance shown whenapplying each FDSS filter varies depending on the specific sequence.

⑥ Among a total of M^(N) sequences, the sequence may be chosen (ordetermined or defined) so as to show a low PAPR characteristic of aspecific threshold or specific level (e.g., Y(> 0) dB) or less eventhough the FDSS filter is not used in K sequences.

⑦ Sequences of a form in which the same phase is multiplied for eachsequence element in a specific length-N sequence are regarded as thesame sequence without being considered as different sequences.

The reason is that when a sequence of a form in which only the phase isshifted is used, a problem occurs in distinguishing the sequence, suchas whether the phase is shifted due to the channel, so it is difficultto use different sequences.

Method 1 above may be applied to a specific antenna port (e.g., specificReference Signal (RS) antenna port) and the same rule may be applied tomultiple antenna ports. Alternatively, some or all rules among the rulesmay be applied (or used) for each antenna by considering characteristicsfor each antenna port.

By considering all of the rules, a sequence may be chosen (or determinedor used), which satisfies all conditions presented above and K sequencesmay be chosen by considering at least one of the rules.

For example, among a total of M^(N) sequences, K sequences are chosen,which show PAPR performance of a specific level/threshold (e.g., X dB)or less when applying the FDSS filter and shows PAPR performance of aspecific level/threshold (e.g., Y dB) or less even when not applying theFDSS filter to be defined (or chosen) as one sequence set.

The sequence and/or sequence set may be used for transmitting thereference and/or data by the UE/eNB.

In addition to the sequences chosen according to a condition dependingon whether to apply the FDSS filter (assuming that the number of chosensequences is K or more), K sequences having a low auto-correlationand/or cyclic-auto correlation of a specific level or less areadditionally chosen to be determined as one sequence set.

K chosen sequences may be defined (or determined) as one sequence setand used by the UE and the eNB and the eNB may indicate/configure to theUE which sequence the UE is to use at a specific time. For reference,the M-PSK and M-QAM symbols mean a Phase shift keying modulation symbolin which a modulation order is M and a Quadrature Amplitude modulationsymbol in which the modulator order is M.

FIG. 13 illustrates one example of a system model and/or a procedure fora DFT-s-OFDM based system.

As an application example of Method 1 above, a CP-OFDM based system anda DFT-s-OFDM based system may be considered. FIG. 13 above illustrates aprocedure (or process) which may be required when Method 1 is applied tothe DFT-s-OFDM based system.

In FIG. 13 above, a length-N sequence set may be configured in variousforms including a sequence set configured by an integer index, asequence set configured by binary information, and the like. Further,the FDSS may not be used due to a transmitter (UE or eNB) implementationcomplexity problem or a problem such as an increase in signaltransmission error which is caused by using the FDSS filter. Byreflecting this, the case of not applying the FDSS and a case ofapplying the FDSS are separately illustrated in FIG. 13 . Further, thismay be selectively applied thereto. Although not illustrated in FIG. 13above, only one of the case of using the FDSS filter and the case of notusing the FDSS filter may be implemented according to implementation ofthe transmitter and the proposed scheme may be still usefully used evenfor the transmitter.

By the above proposed scheme, it is advantageous in that the sequencemay be defined (or designed or chosen) and used by considering variousimplementation schemes of the transmitter.

Method 1-1

When K proposed sequences are used throughout multiple OFDM symbols inthe same slot, the characteristics such as thecross-correlation/auto-correlation among K sequences need to beconsidered.

In two concatenated OFDM symbols, among K sequences, when two sequencesare used by using one sequence per symbol, a sequence first used among Ksequences and a sequence having a smallest cross-correlation may be usedin a next symbol. To this end, a specific sequence and the sequencehaving the smallest cross-correlation may be defined (or determined orconfigured) as one pair. In other words, a specific sequence index u anda sequence index u′ having the smallest cross-correlation may be defined(or configured) as a pair. One example of the one pair may be (u,u′).

Additionally, in Method 1 above, the sequence may be chosen or foundwhile one or all of six rules ①, ②, ③, ④, ⑤, and ⑥ mentioned as the rule(or condition) of K(K ≤ M^(N)) selecting (or choosing) the sequenceaccording to which is a total number value of choosing the sequence. Forexample, it is assumed that the number of chosen sequences is 100 (i.e.,if one sequence set is constituted by 100 sequences) and it is assumedthat a sequence of satisfying all of the six conditions (or rules) isfound. In this case, a maximum allowed cross-correlation value, a cyclicauto-correlation value, and maximum allowable PAPR values when applyingthe filter may be configured to specific values and when the sequence ischosen, the number of available sequences may exceed 100.

Accordingly, the number of sequences to be found may be found whilefixing the number of sequences to be found and changing the conditionsto stronger constraints.

With respect to Method 1 above, a flowchart for a proposed scheme (oralgorithm) may be illustrated as shown in FIG. 14 . Further, respectivesteps of the flowchart may be simultaneously performed or independentlyperformed. Alternatively, an order of the respective steps may bepartially changed.

FIG. 14 is a diagram illustrating a flowchart of Method 1 proposed inthe present disclosure.

In FIG. 14 , first, the transmitter (UE or eNB) determines N and M inorder to find K (> 1) sequences in which the length of each sequence isN (> 1) and each element constituting the sequence is the M-PSK/M-QAMsymbol (S1).

Thereafter, the transmitter 1) configures a PAPR value to be allowedwhen using a specific FDSS filter and a PAPR value to be allowed whennot using the FDSS filter, 2) configures an allowed range/level of thecross-correlation and cyclic auto-correlation values between thesequences, and 3) configures the cyclic shifted sequence to be regardedas the same sequence, in order to determine characteristics of Ksequences to be found (S2).

Thereafter, the transmitter finds a sequence that satisfies apredetermined condition by using the configured values (S3). Here, thetransmitter repeats a process of choosing the sequence by changing oneor more criteria among the configured conditions until K sequences arefound when the number of found sequences exceeds K. Here, if K sequencesare not accurately generated, K sequences may be excluded and discarded.

Thereafter, the transmitter configures or determines a length-N sequenceset with the K chosen sequences (S4).

As a concrete example of the method, 30 sequences (sequence set) inwhich the sequence length is 6 and each element constituting thesequence is configured by 8-PSK symbols may be defined. In other words,in FIG. 13 , a case where N = 6 and M = 8 may be considered.

Method 2

Method 2 proposes that all sequences presented in Table 9 are used, inwhich each sequence element is constituted by 8-(Phase Shift Keying(PSK) symbols and the length is 6 or some of the sequences presented inTable 9 are to be used as uplink PUSCH and/or PUCCH DMRS sequences. Theproposed sequences may be used for Discrete Fourier Transform SpreadOrthogonal Frequency Division Multiplexing (DFT-S-OFDM) and/or CyclicPrefix OFDM (CP-OFDM). In this case, since N=6 and M=8, the total numberof sequences which may be considered is 8⁶. A rule ofgenerating/choosing/using K (> 0) some sequences among a total of 8⁶sequences is as follows. In the proposal, K = 30 is assumed.

A main feature of the proposed sequence is that a low PAPRcharacteristic of X(> 0) dB or less is shown when the FDSS filter (FDSSfilter in which the time-domain response is [0.28 1 0.28]) is appliedand a low PAPR characteristic of Y(> 0) dB is shown even when the FDSSfilter is not applied. More specifically, the proposed sequence has thefollowing characteristics. In other words, it is proposed that theUE/eNB is to use a sequence that satisfies the followingcharacteristics/conditions.

-   It is characterized in that when the FDSS filter (FDSS filter in    which the time-domain response is [0.28 1 0.28]) is applied, the    PAPR is equal to or lower than approximately 2.1 [dB].-   When the FDSS filter is not used, a sequence may be chosen and used,    in which the PAPR is equal to or lower than approximately 2.5 [dB].-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.2357) in +1 and -1    cyclic auto-correlation.-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.4714) in +2, +1, -1,    and -2 cyclic auto-correlation.-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.80474) in +3, +2, +1,    -1, -2, and -3 cyclic auto-correlation.-   Among K chosen sequences, all available cyclic shifted forms of a    specific length-N sequence may be regarded as the same sequence.    Accordingly, among K chosen sequences, no specific sequence is the    same as an available cyclic shifted form of another sequence.

In other words, for example, sequence #1 of Table 9 is ‘-7 -5 -1 5 1 -5’and ‘-5 -1 5 1 -5 -7’ which is a cyclic shift version thereof is thesame sequence.

TABLE 9 index u Sequences ϕ_(u)(n) PAPR [dB] under FDSS filter [0.28 1.00.28] PAPR [dB] without FDSS filter 1 -7 1 -1 -7 3 7 2.1081 2.4678 2 -71 5 3 5 -3 2.0883 2.8683 3 -7 -5 -1 5 1 -5 1.9058 2.4184 4 -7 -5 3 -1 7-5 2.0883 2.8683 5 -7 7 1 -3 3 7 1.9058 2.4184 6 -7 -3 -7 3 1 5 1.98502.2841 7 -7 -1 -5 5 3 5 1.9133 2.5031 8 -7 -3 -1 -3 7 3 1.9133 2.5031 9-7 -3 1 -3 -5 -1 1.7809 2.8344 10 -7 -3 1 -3 7 5 1.9675 2.3452 11 -7 -31 -1 -7 5 1.9850 2.2841 12-7 -3 1 5 1 -51.95582.358113 -7 -3 1 5 3 -3 1.9558 2.3581 14 -7 -1 3 1 3 -3 1.9941 2.8754 15 -7 -13 5 3 -3 1.9058 2.4184 16 -7 3 -1 3 7 -5 1.9850 2.2841 17 -7 3 -1 5 -7-5 1.9133 2.5031 18 -7 3 1 3 7 -3 1.9091 2.5047 19 -7 3 7 5 1 5 1.78092.8344 20 -7 5 -7 -3 7 -5 1.7809 2.8344 21 -7 5 -5 -1 1 -1 1.9091 2.504722 -7 5 -3 -1 -3 1 2.0883 2.8683 23 -7 5 -1 -3 -1 3 1.9058 2.4184 24 -75 -1 -3 1 5 1.9558 2.3581 25 -7 5 -1 1 -1 3 1.9941 2.8754 26 -7 7 7 -3 3-1 1.9133 2.5031 27 -7 7 -5 -1 3 -1 1.9850 2.2841 28 -7 7 -5 1 -3 71.9941 2.8754 29 -7 7 -5 3 -1 7 2.0883 2.8683 30 -7 7 -5 5 -7 -3 1.78092.8344 31 -7 -5 -7 -3 5 1 2.1099 2.8312 32 -7 -5 -1 -7 3 1 2.1081 2.467833 -7 -5 3 1 -5 5 2.1140 2.4372 34 -7 -3 -5 -3 5 1 2.1099 2.8312 35 -7-3 7 1 -1 7 2.1140 2.4372 36 -7 1 -3 5 -7 7 2.1099 2.8312 37 -7 3 -3 1 3-5 2.1140 2.4372 38 -7 7 -1 1 5 -1 2.1140 2.4372

In ϕ_(u)(n) of Table 9, u represents the index of the sequence and nrepresents the element of the sequence (or index of the element). Forexample, when the length of the sequence is 6, n has 0, 1, 2, 3, 4, and5 as shown in Table 10.

In Table 9, for example, when the index u is 1, ϕ₁(0), ϕ₁(1), ϕ₁(2),ϕ₁(3), ϕ₁(4), and ϕ₁(5) correspond to -7, 1, -1, -7, 3, and 7,respectively.

Table 19 above shows one example of an 8-PSK based sequence set(length-6) proposed in the present disclosure and the modulation symbolsare generated by

s_(u)(n) = e^(jϕ_(u)(n)π/8)

.

The PAPR performance is evaluated in DFT-s-OFDM having Comb-2 type DMRSfor one RB (TS 38.211, TS 38.214, and TS 38.331 are referred to forComb-2 type DMRS).

The modulation symbols are generated by

$s_{u}(n) = e^{\frac{j\phi_{\text{u}}{(\text{n})}\text{π}}{8}}$

.

-   ^(u): Sequence index)-   ^(n): Element index of each sequence)

The applied FDSS filter corresponds to the time domain response of [0.281.0 0.28].

-   An IFFT size is 64 and a DFT size is 12.

Excellence in terms of the PAPR performance of the length-6 8-PSKsequence presented in Table 9 above may be confirmed in FIG. 150 . ThePAPR performances of a total of 30 sequences corresponding to #1 to #30among the sequences presented in Table 9 are shown. FIG. 15 above showsthe PAPR performance when the sequence presented in Table 9 above isused as the Comb-2 DMRS sequence in the DFT-S-OFDM system.

The PAPR performance when applying the FDD filter (corresponding to thetime-domain response of [0.28 1.0 0.28]) and the PAPR performance whennot applying the FDSS filter for the presented sequence may beconfirmed.

The PAPR performed is presented by distinguishing whether to apply theFDSS similarly even to the conventional presented length-6 8-PSK. Boththe conventional scheme and the proposed scheme consider that onesequence set is constituted by 30 sequences and are a PAPR evaluationresult therefor. Accordingly, a graph may not be presented withprobability (PAPR > PAPR_0) = 0.1 or less due to the lack of evaluationsamples, but a difference in performance between individual sequencesmay be clearly confirmed. As the conventional presented length-6 8-PSKsequence, sequences presented in R1-1813445, R1-190081, R1-1900020, andR1-1900673 are referred to.

As illustrated in FIG. 15 , the proposed sequence shows a performancesimilar to the PAPR characteristic shown by the conventional presentedsequence when applying the FDSS filter. In particular, it can be seenthat a fine but slightly better performance is shown in a region inwhich probability (PAPR > PAPR_0) = 0.1 or less. When the FDSS filter isnot applied, the PAPR performance deteriorates compared with the FDSSfilter is applied, but a more excellent PAPR performance than theconventional presented sequence may be confirmed. In other words, it maybe confirmed that in 30 proposed sequences, the PAPR does not exceed 2.5dB even when the FDSS filter is not applied unlike the conventionalpresented sequence set (30 sequences are presented as one sequence setin respective references R1-1813445, R1-190081, R1-1900020, andR1-1900673).

FIG. 15 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

The PAPR values presented in Table 9 and FIG. 15 above may be slightlydifferent depending on the IFFT size and a tool for performing asimulation, but a large trend will be similar. Therefore, it may beconsidered that even if there is the slight difference, the slightdifference does not deviate from the spirit of the method presented inthe present disclosure and included in the method proposed in thepresent disclosure. Further, it should be considered that a sequencegenerating/choosing method which exceeds the auto-correlation thresholdis also included in the spirit of the method proposed in the presentdisclosure if the sequence is chosen/used by considering whether to usethe FDSS or not.

Method 2 above may primarily adopt FDSS filter (corresponding totime-domain response [0.28, 1.00, 0.28]), but may be considered as asequence providing a comparable PAPR performance even when the FDSSfilter is not used.

On the contrary, the sequence may be used so that the PAPR performancewhen the FDSS filter is not used is more excellent than the PAPRperformance when a specific FDSS filter is used.

However, it is designed that even when the specific FDSS filter is used,the comparable PAPR performance may be shown. If there are many cases inwhich the FDSS filter is not used due to an increase in error rate,which is caused by distortion of an original transmission signal due totransmitter implementation complexity and/or the use of the FDSS filter,a sequence of a scheme proposed in Method 3 below may be usefully used.

Method 2-2

Method 2-2 relates to a method in which all sequences presented in Table7 are used, in which each sequence element is constituted by 8-(PhaseShift Keying (PSK) symbols and the length is 6 or some of the sequencespresented in Table 7 are used as uplink PUSCH and/or PUCCH DMRSsequences. The proposed sequences may be used for Discrete FourierTransform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM)and/or Cyclic Prefix OFDM (CP-OFDM).

In the case of the method, since N=6 and M=8, the total number ofsequences which may be considered is 8⁶. In this example, a total of twoantenna ports (e.g., two DMRS antenna ports) are considered and eachantenna port is subject to Frequency Division Multiplexing (FDM) in theform of Comb-2. A rule of generating/choosing/using K (> 0) somesequences among a total of 8⁶ sequences is as follows. In the method, K= 45 is assumed.

A main feature of the proposed sequence is that two antenna portssubject to FDM in the form of Comb-2 show a low PAPR characteristic of2.1 dB or less when the FDSS filter (FDSS filter in which thetime-domain response is [0.28 1 0.28]) is applied and a low PAPRcharacteristic of 2.3 dB even when the FDSS filter is not applied.

Additionally, the proposed sequence has the following characteristics.

-   The proposed sequence has a characteristic that the maximum cyclic    auto-correlation is equal to or smaller than approximately 0.2357 in    +1 and -1 cyclic auto-correlation lags.-   The proposed sequence has a characteristic that the maximum cyclic    auto-correlation is equal to or smaller than approximately 0.8 in    +3, +2, +1, -1, -2, and -3 cyclic auto-correlation lags.-   Among K chosen sequences, all available cyclic shifted forms of a    specific length-N sequence may be regarded as the same sequence.    Accordingly, among K chosen sequences, no specific sequence is the    same as an available cyclic shifted form of another sequence.

In other words, for example, sequence #1 of Table 10 is ‘-7 -5 -1 5 1-5’ and ‘-5 -1 5 1 -5 -7’ which is a cyclic shift version thereof is thesame sequence.

TABLE 10 index u Sequences ϕ_(u)(n) PAPR [dB] under FDSS filter for the1^(st) port PAPR [dB] under FDSS filter for the 2^(nd) port PAPR [dB]without FDSS filter for both ports 1. -7 -7 -5 1 -5 3 1.8602 2.01112.2792 2. -7 -5 -5 1 -7 3 1.8544 2.0157 2.2830 3. -7 -5 -1 -7 -5 51.5917 1.1343 1.8125 4. -7 -3 -7 -3 5 1 1.1298 1.5228 1.6323 5. ^(_)7 -3-5 -1 5 1 1.5775 1.8365 2.1090 6. -7 -3 -5 -1 7 1 1.8403 1.2296 1.46347. -7 -3 -5 -1 7 3 1.5775 1.8365 2.1090 8. -7 -3 1 -5 5 3 1.6229 1.82702.1422 9. -7 -3 1 -5 7 3 1.3980 1.8686 1.4299 10. -7 -3 1 -3 7 3 1.27151.8500 2.2025 11. -7 -3 1 7 3 -1 1.4188 1.8577 1.3790 12. -7 -1 -5 3 7 51.5775 1.8365 2.1090 13. -7 -1 1 -7 3 1 1.9140 2.0557 1.9783 14. -7 1 -51 3 3 1.8544 2.0157 2.2830 15. -7 1 -3 1 5 1 1.8693 1.7879 2.0393 16. -71 -3 3 7 5 1.5775 1.8365 2.1090 17. -7 1 3 3 -3 3 2.0740 1.9021 2.049318. -7 1 5 1 -3 1 1.8762 1.7764 1.9936 19. -7 3 -5 -1 -3 1 1.8318 1.23771.4984 20. -7 3 -5 1 1 3 1.8602 2.0111 2.2792 21. -7 3 -3 -5 -1 3 1.99711.5769 1.7233 22. -7 3 1 -7 -3 1 1.7805 1.5540 1.8564 23, -7 3 1 -5 -1 31.9405 1.4918 2.0507 24. -7 3 1 -5 1 3 1.8712 1.8673 1.1808 25. -7 3 1 5-1 3 1.7987 1.8941 2.2224 26. -7 3 3 5 -3 3 2.0908 1.9001 2.0476 27. -73 5 -1 3 5 1.5780 1.1347 1.8558 28. -7 3 5 7 1 -3 1.6121 1.9126 1.247229. -7 5 -7 -3 3 -1 1.2715 1.8500 2.2025 30. -7 5 -5 -3 3 -1 1.45442.0850 1.7632 31. -7 5 -5 -1 -3 1 1.5769 1.8271 2.1872 32. -7 5 -5 -1 3-1 1.3007 1.8495 2.2771 33. -7 5 -3 1 -3 1 1.1521 1.5386 1.6826 34. -7 5-3 1 -1 3 1.5886 1.8200 2.1604 35. -7 5 -1 -5 -1 3 1.3064 1.8552 2.275836. -7 5 -1 1 3 -3 1.6196 1.9058 1.2817 37. -7 5 1 -7 -3 1 1.6825 1.73491.5684 38. -7 5 1 -5 -1 3 1.4188 1.8577 1.3790 39. -7 5 1 5 -7 -1 2.03761.7490 1.8846 40. -7 5 1 7 -5 -1 1.3980 1.8686 1.4299 41. -7 7 -5 1 -3 51.5886 1.8200 2.1604 42. -7 7 -5 3 -1 5 1.5769 1.8271 2.1872 43. -7 7 1-7 -5 1 1.9270 2.0557 1.9546 44. -7 7 1 -7 -3 1 1.7795 1.5824 1.8210 45.-7 7 1 -5 -1 3 1.6275 1.8289 2.0924

Table 10 shows one example of an 8-PSK based sequence set (length-6)proposed in the present disclosure. Here, the modulation symbols aregenerated by

s_(u)(n) = e^(jϕ_(u)(n)π/8)

. The PAPR performance is evaluated in DFT-s-OFDM having Comb-2 typeDMRS for one RB (TS 38.211, TS 38.214, and TS 38.331 are referred to forComb-2 type DMRS).

The modulation symbols are generated by

$s_{u}(n) = e^{\frac{j\phi_{u}{(n)}\pi}{8}}$

-   ^(u): Sequence index)-   ^(n): Element index of each sequence).-   The applied FDSS filter corresponds to a time domain response of    [0.28 1.0 0.28].-   An IFFT size is 64 and a DFT size is 12.

It is proposed that some or all of the sequences presented in Table 10above are used. Further, some or all of the sequences presented in Table10 above and sequences (having different characteristics) not presentedin the above table and one sequence set may be constituted and used. Itmay be considered that such a constitution as an extension (orapplication) of the present disclosure is included in the spirit of themethod proposed in the present disclosure.

In FIG. 16 , the excellence of the sequence proposed in Method 2-2 abovemay be confirmed. Compared with the conventional sequence, the proposedsequence shows the low PAPR characteristic in both the case of using theFDSS filter and the case of not using the FDSS filter. In particular, inthe case of not using the FDSS filter, a difference in PAPR performancebetween the sequence presented in Method 2-2 and the conventionalsequence is significantly large.

FIG. 16 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

In Methods 2 and 2-1 above, a length-6 DMRS sequence (Pre-DFT length-6sequence) is mapped to a time-frequency resource element (RE) by thefollowing scheme.

It is characterized in that when frequency-RE is used as Comb-2 type inthe frequency domain, a time-axis signal is shown repeatedly twice.Accordingly, in order to transmit the length-6 DMRS sequence in a stepbefore DFT in the DFT-spread-OFDM system, the length-6 sequence needs tobe used by considering that the length-6 sequence is repeated twice inthe time domain. Accordingly, in a (pre-)DFT procedure, the length-6sequence should be used to be repeated twice.

$x_{2N} = D_{DFT}\begin{bmatrix}S_{N} \\S_{N}\end{bmatrix}$

Here, D_(DFT) represents a Discrete Fourier Transform (DFT) matrix.

S_(N) = [S₁,S₂,...,S₆] represents a 6 x 1 vector (one length-6sequence). Here, each element S_(i) represents M-PSK/M-QAM symbol.

x_(2N) represents a 12 x 1 vector which is a frequency-domain signalafter DFT processing of

$\begin{bmatrix}S_{N} \\S_{N}\end{bmatrix}$

.

In this case, when the DMRS sequence is transmitted by theDFT-spread-OFDM scheme, a DFT computation is performed by using a formin which the length-6 sequence is repeated twice in the pre-DFT step asmentioned above at the time of transmitting a single-port DMRS.

When the number of DMRS ports is 2, a specific DMRS port may beconfigured in a comb-2 type in which a frequency offset is 0 and theother DMRS port may be configured in a comb-2 type in which thefrequency offset is 1. In this case, when the length-6 sequence to beused in the second DMRS port and the length-6 sequence to be used in thefirst DMRS port are mapped to a frequency axis through a (pre-)DFTprocess as shown in Equation 8 above, both the length-6 sequences areallocated to a Comb-2 structure (comb-2 structure in which the frequencyoffset is 0) having frequency offset “0”.

When the length-6 sequence to be used in the second DMRS port is mappedto the frequency axis through the (pre-)DFT process as shown in Equation8 above, the length-6 sequence is allocated to the Comb-2 structurehaving frequency offset “0”. The length-6 sequence is allocatedaccording to Equation 9 below instead of Equation 8 in order to allocatethe length-6 sequence to the Comb-2 structure having frequency offset“1” so as to prevent the first DMRS port and the RE from beingoverlapped with each other.

$x_{2N} = KD_{DFT}\begin{bmatrix}S_{N} \\S_{N}\end{bmatrix}$

$\text{K} = \begin{bmatrix}0_{1 \times 12} \\{1\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0} \\0_{1 \times 12} \\{0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0} \\0_{1 = 12} \\{0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0} \\0_{1\mspace{2mu} \times 12} \\{0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0} \\0_{1 \times 12} \\{0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0} \\0_{1 = 12} \\{0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 0\mspace{6mu}\mspace{6mu} 1\mspace{6mu}\mspace{6mu} 0}\end{bmatrix}$

In Equation 9 above, K is a 12 x 12 matrix and a matrix which allowselements allocated to an odd-numbered subcarrier resource element (RE)to be allocated to an even-numbered subcarrier RE.

Method 3

Method 3 relates to a method in which all sequences presented in Table11 are used, in which each sequence element is constituted by 12-(PhaseShift Keying (PSK) symbols and the length is 6 or some of the sequencespresented in Table 11 are used as uplink PUSCH and/or PUCCH DMRSsequences. The proposed sequences may be used for Discrete FourierTransform Spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM)and/or Cyclic Prefix OFDM (CP-OFDM).

In the case of the method, since N=6 and M=8, the total number ofsequences which may be considered is 8⁶.

A rule of generating (or choosing or using) K (> 0) some sequences amonga total of 8⁶ sequences is as follows.

A main feature of the sequence proposed in the present disclosure isthat the low PAPR characteristic of Y (> 0) or less is shown when theFDSS filter is not used and the PAPR performance is less excellent whenthe FDSS filter (FDSS filter in which the time-domain response is [0.281 0.28]) than the PAPR performance when the FDSS filter is not used, butthe low PAPR characteristic of X (> 0) dB or less is still shown. Morespecifically, the proposed sequence has the following characteristics.In other words, it is proposed that the UE/eNB is to use a sequence thatsatisfies the following characteristics/conditions.

-   It is characterized in that when the FDSS filter (FDSS filter in    which the time-domain response is [0.28 1 0.28]) is applied, the    PAPR is equal to or lower than approximately 2.8 [dB].-   When the FDSS filter is not used, a sequence may be chosen and used,    in which the PAPR is equal to or lower than approximately 2.1 [dB],-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.2357) in +1 and -1    cyclic auto-correlation.-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.4714) in +2, +1, -1,    and -2 cyclic auto-correlation.-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.80474) in +3, +2, +1,    -1, -2, and -3 cyclic auto-correlation.-   Among K chosen sequences, all available cyclic shifted forms of a    specific length-N sequence may be regarded as the same sequence.    Accordingly, among K chosen sequences, no specific sequence is the    same as an available cyclic shifted form of another sequence.

TABLE 11 Sequence index u Sequences Φ_(u)(n) PAPR [dB] under FDSS filter[0.28 1.0 0.28] PAPR [dB] without FDSS filter 1. -7 -7 -5 1 -5 5 2.27751.7169 2. -7 -7 3 -7 -5 -1 2.5231 2.0790 3. -7 -5 -7 3 -3 5 2.52171.9843 4. -7 -5 -5 -3 5 1 2.5607 2.0547 5. -7 -5 -5 -1 -7 3 2.27281.7325 6. -7 -5 -1 7 1 -5 2.5422 2.0851 7. -7 -5 1 -5 -7 5 2.7798 1.95498. -7 -5 1 -5 -5 5 2.5223 2.0798 9. -7 -5 3 -1 7 -7 2.5529 2.0873 10. -7-3 -7 7 1 7 2.7798 1.9549 -7 -3 -3 -1 5 -1 2.2728 1.7325 12. -7 -3 -1 -37 1 2.5370 2.0877 13. -7 -3 -1 5 -1 -3 2.7821 1.8653 14. -7 -3 -1 5 -1-1 2.5344 1.9917 15. -7 -3 5 -1 -7 7 2.5217 1.9843 16. -7 -3 7 1 7 -72.2775 1.7169 17. -7 -3 7 7 1 7 2.5223 2.0798 18. -7 -1 -7 -7 3 7 2.52312.0790 19. -7 -1 -7 3 7 7 2.2728 1.7325 20. -7 -1 1 1 5 -1 2.2775 1.716921. -7 -1 1 5 -1 -1 2.5344 1.9917 22. -7 -1 1 5 1 -1 2.7821 1.8653 23.-7 1 -5 5 3 5 2.5370 2.0877 24. -7 1 -3 5 7 7 2.5607 2.0547 25. -7 1 3 35 -3 2.5529 2.0873 26. -7 1 5 7 5 -1 2.5422 2.0851 27. -7 3 -7 -5 -1 -52.7798 1.9549 28. -7 3 -5 -1 1 -1 2.5217 1.9843 29. -7 3 -3 -5 -3 12.5422 2.0851 30. -7 3 -3 1 1 3 2.2775 1.7169 31. -7 3 -3 3 5 5 2.27281.7325 32. -7 3 1 -3 1 3 2.7821 1.8653 33. -7 3 1 3 7 -1 2.5217 1.984334. -7 3 3 -3 1 3 2.5344 1.9917 35. -7 3 3 -3: 3 5 2.5344 1.9917 36. -75 -3 -1 -1 1 2.5529 2.0873 37. -7 5 3 -3 3 5 2.7821 1.8653 38. -7 7 1 -53 7 2.5422 2.0851 39. -7 7 3 7 -7 -1 2.7798 1.9549

Table 11 shows one example of a proposed 8-PSK based sequence set(length-6). The modulation symbols are generated by

s_(u)(n) = e^(jϕ_(u)(n)π/8)

. The PAPR performance is evaluated in the DFT-s-OFDM system having theComb-2 type DMRS for one RB.

FIG. 17 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

An advantage of the length-6 8-PSK sequence presented in Table 11 abovemay be seen in FIG. 17 . FIG. 17 above illustrates the PAPR performancewhen the sequence presented in Table 11 above is used as the Comb-2 DMRSsequence in the DFT-S-OFDM system. The PAPR performance when applyingthe FDD filter (corresponding to the time-domain response of [0.28 1.00.28]) and the PAPR performance when not applying the FDSS filter forthe presented sequence are shown. It may be confirmed that the sequencedefined according to Method 3 above shows the PAPR performance of 2.1 dBor less when the FDSS filter is not used.

Methods 2 and 3 above relate to a method that uses a sequence whichshows the low PAPR characteristic in a case of applying the FDSS filter(in particular, an FDSS filter in which the time-domain responsecorresponds to [0.28 1.00 0.28]) and in a case of not applying the FDSSfilter, i.e., both cases with respect to the same specific sequence.

However, when the sequence having the low PAPR characteristic isdetermined (or used) by considering only the case where the FDSS filteris not used or the sequence having the low PAPR characteristic isdetermined (or used) by assuming only the FDSS filter, a sequence havinga lower PAPR characteristic than the sequence in the above case may beused. In other words, since there is a limit that the PAPR performanceis good in both the case of applying the filter and the case of notapplying the filter, the following method is proposed by consideringthat there is the limit that the PAPR performance is good.

Method 4

Method 4 relates to a method in which elements constituting one sequenceare M-PSK/M-QAM symbols and one sequence set is constituted by a totalof K sequences having a sequence length of N and K₁(> 0) sequences inwhich a specific PAPR has an excellent characteristic are used when aspecific FDSS filter is used and K₂(> 0) sequences having the excellentPAPR characteristic are used when the FDSS filter is not used.

The total number of sequences constituting one sequence set is K = K₁+K₂.

By considering multiple environments such as whether specific FDSSfilters are used a lot or whether the FDSS filter is not primarily used,the K₁ and K₂ may be considered. For example, if K length-N sequencesare defined (or constituted or used) by considering that the specificFDSS filter is primarily used, a sequence set of K₁ >> K₂ > 0 may beconstituted.

Alternatively, if one sequence set is constituted (or determined) (Ksequences are constituted (or determined) by targeting the case wherethe FDSS filter is not used, a sequence set of K₂ >> K₁ > 0 may beconstituted (or determined). For example, by assuming K = 30, an extremecase such as a case of K₁ = 27, K₂ = 3 may be considered.

For example, if 30 sequences constitute one sequence set by consideringthe length-6 sequence constituted by 8-PSK symbols, a sequence presentedin Table 12 below may be used. It is proposed that some or all of thesequences are used as a reference signal sequence such as the DMRS inthe DFT-s-OFDM system.

-   Table 12 below is configured by assuming K = K₁ + K₂ = 47.

As shown in Table 12, sequences #1 to #15 are sequence to use not usingthe FDSS filter as a main target and sequences #16 to #30 are sequenceswhich will consider that FDSS filters corresponding to the time-domainresponse [0.28 1.0 0.28] are together used and uses together using theFDSS filters as a target. A PAPR performance difference depending onwhether to use the filter may be confirmed in Table 13 presented.Further, the following sequence is configured to have the followingcharacteristics.

-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.2357) in +1 and -1    cyclic auto-correlation.-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.4714) in +2, +1, -1,    and -2 cyclic auto-correlation.-   It is characterized in that the maximum cyclic auto-correlation is    low (equal to or smaller than approximately 0.80474) in +3, +2, +1,    -1, -2, and -3 cyclic auto-correlation.-   Among K chosen sequences, all available cyclic shifted forms of a    specific length-N sequence may be regarded as the same sequence.    Accordingly, among K chosen sequences, no specific sequence is the    same as an available cyclic shifted form of another sequence.-   It is configured so that there is no sequence of a form in which    only the phase is just shifted among K chosen sequences. In other    words, sequences of a form in which six sequence elements are    multiplied by the same phase are regarded as the same sequence and    excluded. In Table 12 below, a first sequence element of each    sequence is fixed to -7, but when all of 6 elements corresponding to    each sequence should are similarly phase-shifted, each sequence    should be regarded as the same sequence. In other words, although    not presented in Table 12 below, it can be seen that when the    following sequence is phase-shifted, each sequence which is the same    sequence is included in the sequence proposed in the present    disclosure.

TABLE 12 Sequence index u Sequences ϕ_(u)(n) PAPR [dB] under FDSS filter[0.28 1.0 0.28] PAPR [dB] without FDSS filter 1. -7 -7 -5 1 -5 5 2.27751.7169 2. -7 -7 -5 1 -5 7 3.2781 1.8879 3. -7 -5 -5 -1 -7 3 2.27281.7325 4. -7 -5 7 1 7 -7 3.2781 1.8879 5. -7 -3 -3 -1 5 -1 2.2728 1.73256. -7 -3 -1 5 -1 -3 2.7821 1.8653 7. -7 -3 7 1 7 -7 2.2775 1.7169 8. -7-1 -7 3 7 7 2.2728 1.7325 9. -7 -1 1 1 3 -1 3.2781 1.8879 10. -7 -1 1 15 -1 2.2775 1.7169 11. -7 -1 1 5 1 -1 2.7821 1.8653 12. -7 3 -3 1 1 32.2775 1.7169 13. -7 3 -3 3 5 5 2.2728 1.7325 14. -7 3 -1 1 1 3 3.27811.8879 15. -7 3 1 -3 1 3 2.7821 1.8653 16. -7 -3 -7 -3 -5 5 1.59453.4043 17. -7 -3 -7 -3 1 -5 1.5945 3.4043 18. -7 -3 -7 -3 1 -1 1.44623.1777 19. -7 -3 -7 5 -7 -3 1.5120 3.4679 20. -7 -3 -5 -1 3 -1 1.44153.6409 21. -7 -3 1 -3 -7 -3 1.5311 3.5024 22. -7 -3 1 -3 1 -5 1.45973.1244 23. -7 -3 1 -3 1 -3 1.5120 3.4679 24. -7 -3 1 -3 7 -5 1.43713.5745 25. -7 -3 1 -1 3 -3 1.4300 3.5842 26. -7 -3 1 5 1 -3 0.78393.0103 27. -7 -3 7 3 7 -5 1.4300 3.5842 28. -7 -3 7 5 -7 -3 1.45973.1244 29. -7 -3 7 5 -7 5 1.5945 3.4043 30. -7 3 -1 3 7 5 1.4415 3.640931. -7 3 1 5 -7 5 1.4462 3.1777 32. -7 3 7 3 7 -5 1.4609 3.1778 33. -7 37 5 -7 -3 1.4371 3.5745 34. -7 5 -7 -3 -7 5 1.5120 3.4679 35. -75 -7 -3-5 -1 1.4371 3.5745 36. -7 5 -7 -3 -5 5 1.4597 3.1244 37. -7 5 -7 -3 1-3 0.7788 2.9581 38. -7 5 -7 5 1 5 1.5311 3.5024 39. -7 5 -1 3 1 51.4300 3.5842 40. -7 5 1 -3 1 5 0.7839 3.0103 41. -7 5 1 5 -7 -3 0.77882.9581 42. -7 5 1 5 1 5 1.5120 3.4679 43. -7 7 -5 -1 -5 -1 1.4609 3.177844. -7 7 -5 -1 -5 5 1.4300 3.5842 45. -7 7 -5 5 1 5 1.4371 3.5745 46. -77 1 5 -7 5 1.5945 3.4043 47. -7 7 1 5 1 5 1.4597 3.1244

Table 12 shows one example of the proposed 8-PSK based sequence set(length-6) and the modulation symbols are generated by

s_(u)(n) = e^(jΦ_(u)(n)π/8)

. The PAPR performance is evaluated in the DFT-s-OFDM system having theComb-2 type DMRS for one RB.

In Table 12 above, sequences #1 to #15 are sequence to use not using theFDSS filter as a main target and sequences #16 to #47 are sequenceswhich choose (or determine or configure) the case of using the FDSSfilter corresponding to the time-domain response [0.28 1.0 0.28] as thetarget.

Method 5

In Method 5, it is apparent that when the FDSS filter is used, the PAPRcharacteristic is improved with probability, but the PAPR is notoptimized in terms of each sequence. As described in the presentdisclosure, it can be seen that a specific FDSS filter is applied to aspecific sequence, the PAPR characteristic of the specific sequencedeteriorates.

Based thereon, it is proposed that the transmitter uses different FDSSfilters according to a sequence, a sequence group, and/or a set ofsequences (sub set) transmitted. Further, one sequence set optimized tothe used FDSS filter is constituted (or determined) to be used by theUE/eNB. As one example, a system/device illustrated in FIG. 19 may beconsidered. Different sequences may be used for each specific RB(s)and/or for each a group of RB(s) and the transmitter may use differentsequences for each OFDM symbol and/or for each slot(s).

In order for a receiver to help approximately reconstructing differentsequences, the transmitter may inform the receiver of which FDSS filteris to used in the specific sequence. In addition/alternatively, thereceiver may indicate to the transmitter which filter is to be used foreach specific sequence and for each sequence group. Alternatively, thereceiver and the transmitter may predefine (or promise) which FDSSfilter is used for which sequence and use the corresponding FDSS filter.

One sequence set/group/table is constituted and sequences may be used,which are optimized to FDSS filter #1, FDSS filter #2,..., FDSS filter#D used. In other words, D optimized sequence groups/sub-sets areconfigured, to which the PAPR performance (and/or including variouscriteria/performances such as cross-correlation/auto-correlation) isoptimized by using the FDSS filter with respect to D FDSS filters to beused and defined (or configured) as one set/group, and as a result, thetransmitter may be used for transmitting the reference signals includingthe DMRS, the SRS, the CSI-RS, and the like.

Additionally, by considering even the case of not using the FDSS filter,a total of (D + 1) sequence groups (or sub-sets) in which the PAPRperformance is optimized are constituted with respect to the case ofusing D FDSS filters and the case of not using the FDSS filter and onesequence set/group/table is constituted, and as a result, thetransmitter may be used for transmitting the reference signal/datasignal.

FIG. 18 illustrates one example for adaptively applying an FDSS filterproposed in the present disclosure.

NR Rel-16 supports binary CGS in Tables 1, 2, and 3 with respect tolengths 12, 18, and 14, respectively and then pi/2 BPSK modulation isfollowed, and then DFT is followed as a DMRS sequence for π/2 BPSKmodulation with respect to both the PUSCH and the PUCCH.

The above contents are applicable to a single DMRS configuration. CGSfor a 2-symbol DMRS configuration may be discussed. Tables 1, 2, and 3may be discovered in R1-1901362.

Here, the CGS may be used up to length-8 and 8-PSK may be used forlength-6.

Hereinafter, in the 2-symbol DMRS configuration, a computer generationsequence applying method will be described.

In two symbols, the same computer generate sequence (CGS) may be used.

In a CGS set (among 30 sequences), when a specific sequence is used in afirst symbol, the specific sequence is configured to be used in a nextsymbol in link therewith.

In this case, among other sequences other than the specific sequenceused in the first symbol, a sequence having a lowest cross-correlationwith the specific sequence used in the first symbol may be used in asecond symbol in a sequence set/group/table.

Alternatively, according to another criterion, two sequences may be madeinto one pair and predetermined (or defined) to be used in twoconcatenated OFDM symbols or the eNB may configure (or indicate) thesequence pair to the UE.

It is conceivable that independent computer generation sequences (CGSs)are used with respect to a first (1^(st)) DMRS symbol and a second(2^(nd)) DMRS symbol, respectively.

To this end, 30 CGSs are defined per symbol to define a total of 60CGSs. In this case, 30 sequences may be considered as one sequence set.

In this case, it may be considered that the sequence set is defined sothat the cross-correlation between two sequence sets is minimized.Alternatively, when the specific sequence is used in the first (1^(st))DRMS symbol, a specific sequence and/or specific sequence sub-set (someof 30 sequences) to be used in the second (2^(nd)) DMRS symbol may beused.

8-PSK is used with respect to length-6 CGS.

In the case of PUSCH having one OFDM symbol DMRS and pi/2 BPSKmodulation, one of the following alternatives is selected.

Alternative 0: Only a single DMRS is supported (one comb is used).

Alternative 1: One DMRS port is supported per comb (in a total of 2ports).

Alternative 2: Two DMRS ports are supported per comb (in a total of 4ports).

Hereinafter, an additional embodiment for Method 2 described above willbe described through Method 2-1.

Method 2-1

Method 2-1 relates to relaxing the cyclic auto-correlation performancein Method 2 above. A sequence having a better PAPR characteristic may beused through relaxation and there may be a method in which the number ofsequences constituting one sequence set is significantly increased toselectively/adaptively use the sequences. In Method 2, when thecondition of Method 2 is relaxed under a condition in which the PAPR is2.3 dB or less at the time of using the FDSS filter and the PAPR is 3.2dB or less at the time of not using the FDSS filter, sequences presentedin Table 13 below may be obtained. It is proposed that one or more somesequences or all sequences of the sequences presented in Table 13 aboveare used as the DFT-spread-OFDM based DMRS sequence.

TABLE 13 Sequence index u Sequences ϕ_(u)(n) PAPR [dB] under FDSS filter[0.28 1.0 0.28] PAPR [dB] without FDSS filter 1. -7 -7 -5 1 -5 5 2.27751.7169 2. -7 -7 -3 3 -1 -7 2.2833 2.9253 3. -7 -7 3 -1 5 -7 2.28332.9253 4. -7 -5 -7 -3 3 -1 1.9710 2.9166 5. -7 -5 -7 -3 5 1 2.10992.8312 6. -7 -5 -7 -1 5 1 2.0214 3.0285 7. -7 -5 -5 -1 -7 3 2.27281.7325 8. -7 -5 -1 -7 3 1 2.1081 2.4678 9. -7 -5 -1 5 1 -5 1.9058 2.418410. -7 -5 -1 5 1 -3 2.1617 2.5641 11. -7 -5 -1 7 5 -1 2.2544 2.9451 12.-7 -5 3 -1 5 -5 1.9966 3.1184 13. -7 -5 3 -1 7 -5 2.0883 2.8683 14. -7-5 3 1 -5 5 2.1140 2.4372 15. -7 -5 3 7 5 -1 1.9282 3.0378 16. -7 -5 5-1 -3 1 1.9385 3.1365 17. -7 -5 5 -1 -3 5 2.2274 2.8838 18. -7 -5 5 1 7-5 1.9941 2.8754 19. -7 -5 7 3 -1 5 2.1652 2.6502 20. -7 -3 -7 -3 1 -11.4462 3.1777 21. -7 -3 -7 3 1 5 1.9850 2.2841 22. -7 -3 -5 -3 5 12.1099 2.8312 23. -7 -3 -5 -3 7 3 1.9710 2.9166 24. -7 -3 -5 5 -1 11.9500 3.1462 25. -7 -3 -5 5 1 3 2.2957 3.1261 26. -7 -3 -5 5 1 5 1.96752.3452 27. -7 -3 -5 7 -5 -1 1.7721 2.9294 28. -7 -3 -3 -3 7 3 2.29143.0354 29. -7 -3 -3 -1 5 -1 2.2728 1.7325 30. -7 -3 -1 -5 7 3 2.13872.6592 31. -7 -3 -1 -3 7 3 1.9133 2.5031 32. -7 -3 -1 7 5 -1 2.12892.4781 33. -7 -3 1 -5 -1 -3 1.7721 2.9294 34. -7 -3 1 -3 -5 -1 1.78092.8344 35. -7 -3 1 -3 1 -5 1.4597 3.1244 36. -7 -3 1 -3 7 5 1.96752.3452 37. -7 -3 1 -1 -7 5 1.9850 2.2841 38. -7 -3 1 5 1 -5 1.95582.3581 39. -7 -3 1 5 1 -3 0.7839 3.0103 40. -7 -3 1 5 3 -3 1.9558 2.358141. -7 -3 3 -1 -5 7 2.1652 2.6502 42. -7 -3 5 3 -3 7 2.2274 2.8838 43.-7 -3 5 v; 1 -5 1.9282 3.0378 44. -7 -3 7 -5 -1 -5 1.7592 2.9005 45. -7-3 7 1 -1 7 2.1140 2.4372 46. -7 -3 7 1 7 -7 2.2775 1.7169 47. -7 -3 7 5-7 -3 1.4597 3.1244 48. -7 -1 -7 3 7 7 2.2728 1.7325 49. -7 -1 -5 3 5 32.0214 3.0285 50. -7 -1 -5 5 3 5 1.9133 2.5031 51. -7 -1 -5 5 5 5 2.29143.0354 52. -7 -1 -5 5 7 5 1.9710 2.9166 53. -7 -1 -5 7 3 5 2.1387 2.659254. -7 -1 -3 -1 7 3 2.0214 3.0285 55. -7 -1 1 -3 7 5 2.2957 3.1261 56.-7 -1 1 1 5 -1 2.2775 1.71.69 57. -7 -1 3 1 3 -3 1.9941 2.8754 58. -7 -13 3 3 -3 2.2833 2.920.53 59. - 7 -1 3 5 1 -3 2.1617 2.5641 60. -7 -1 3 53 -3 1.9058 2.4184 61. -7 -1 5 3 5 -3 1.9966 3.1184 62. -7 1 -3 3 -7 72.0214 3.0285 63. -7 1 -3 5 -7 7 2.1099 2.8312 64. -7 1 -3 5 7 5 2.10992.8312 65. -7 1 -1 -7 3 7 2.1081 2.4678 66. -7 1 3 -3 7 5 1.9500 3.146267. -7 1 3 1 5 -3 2.0805 2.9022 68. -7 1 3 1 7 -3 1.9909 3.1248 69. -7 13 7 1 -5 2.1289 2.4781 70. -7 1 5 3 -3 7 1.9385 3.1365 71. -7 1 5 3 5 -32.0883 2.8683 72. -7 1 5 7 1 -5 2.2544 2.9451 73. -7 3 -3 -5 -1 7 1.92823.0378 74. -7 3 -3 -5 3 5 2.1289 2.4781 75. -7 3 -3 -5 3 7 2.2544 2.945176. -7 3 -3 -1 3 -5 2.2274 2.8838 77. -7 3 -3 -1 7 -5 1.9385 3.1365 78.-7 3 -3 1 1 3 2.2775 1.7169 79. -7 3 -3 1 3 -5 2.1140 2.4372 80. -7 3 -33 5 5 2.2728 1.7325 81. -7 3 -1 3 7 -5 1.9850 2.2841 82. -7 3 -1 5 -7 -51.9133 2.5031 83. -7 3 -1 5 -7 7 1.9710 2.9166 84. -7 3 1 -7 -3 -12.2631 2.9654 85. -7 3 1 3 7 -3 1.9091 2.5047 86. -7 3 1 5 -7 5 1.44623.1777 87. -7 3 1 5 -5 -3 2.2957 3.1261 88. -7 3 1 5 -3 -1 1.9500 3.146289. -7 3 5 -7 1 -1 2.2631 2.9654 90. -7 3 5 -3 1 -1 1.9500 3.1462 91. -73 5 3 7 -3 1.9801 2.9603 92. -7 3 7 -5 7 5 1.7721 2.9294 93. -7 3 7 3 7-5 1.4609 3.1778 94, -7 3 7 5 1 5 1.7809 2.8344 95. -7 5 -7 -3 -5 51.4597 3.1244 96. -7 5 -7-3 1 -3 0.7788 2.9581 97. -7 5 -7 -3 7 -51.7809 2.8344 98, -7 5 -5 -1 -3 -1 1.9801 2.9603 99. -7 5 -5 -1 1 -32.1652 2.6502 100. -7 5 -5 -1 1 -1 1.9091 2.5047 101. -7 5 -5 1 -1 11.9909 3.1248 102. -7 5 -3 -1 -3 1 2.0883 2.8683 103. -7 5 -3 -1 -3 31.9966 3.1184 104. -7 5 -3 1 -1 1 2.0805 2.9022 105. -7 5 -1 -3 -1 31.9058 2.4184 106. -7 5 -1 -3 1 5 1.9558 2.3581 107. -7 5 -1 -1 -1 32.2833 2.9253 108. -7 5 -1 1 -1 3 1.9941 2.8754 109. -7 5 1 -3 -1 32.1617 2.5641 110. -7 5 1 -3 1 5 0.7839 3.0103 111. -7 5 1 -3 3 7 2.16172.5641 112. -7 5 1 3 7 -3 2.1652 2.6502 113. -7 5 1 5 -7 -3 0.77882.9581 114. -7 5 1 7 -5 -3 2.1387 2.6592 115. -7 5 3 7 1. 5 1.77212.9294 116. -7 5 7 -5 1 -3 2.1387 2.6592 117. -7 5 7 -3 1 -1 2.29573.1261 113. -7 7 -7 -3 3 -1 1.9133 2.5031 119. -7 7 -5 -1 -5 -1 1.46093.1778 120. -7 7 -5 -1 3 -1 1.9850 2.2841 121. -7 7 -5 1 -3 7 1.99412.8754 122. -7 7 -5 3 -1 7 2.0883 2.8683 123. -7 7 -5 3 5 -1 1.93853.1365 124. -7 7 -5 5 -7 -3 1.7809 2.8344 125. -7 7 -3 3 -1 7 1.99663.1184 126. -7 7 -1 1 5 -1 2.1140 2.4372 127. -7 7 -1 3 5 -1, 2.22742.8838 128. -7 7 1 -5 -3 1 2.2544 2.9451 129. -7 7 1 -5 -3 5 1.92823.0378 130. -7 7 1 -5 -1 1 2.1289 2.4781 131. -7 7 1 -3 1 5 1.95582.3581 132. -7 7 1 -3 3 7 1.9058 2.4184 133. -7 7 1 5 1 5 1.4597 3.1244134. -7 7 3 7 -5 5 1.7592 2.9005

Table 13 shows one example of the proposed 8-PSK based sequence set(length-6) and the modulation symbols are generated by

s_(u)(n) = e^(jϕ_(u)(n)π/8)

. The PAPR performance is evaluated in the DFT-s-OFDM system having theComb-2 type DMRS for one RB.

Method 6

In Method 6, it is characterized in that when frequency-RE is used asComb-2 type in the frequency domain, a time-axis signal is shownrepeatedly twice. Accordingly, in order to transmit the length-6 DMRSsequence in a step before DFT in the DFT-spread-OFDM system, thelength-6 sequence needs to be used by considering that the length-6sequence is repeated twice in the time domain. Accordingly, in a(pre-)DFT procedure, the length-6 sequence should be used to be repeatedtwice.

$x_{2N} = D_{DFT}\begin{bmatrix}S_{N} \\S_{N}\end{bmatrix}$

Here, D_(DFT) represents a Discrete Fourier Transform (DFT) matrix.

s_(N) = [s₁, s₂, ..., s₆] represents a 6 x 1 vector (one length-6sequence) and each element s_(i) represents the M-PSK/M-QAM symbol.

x_(2N) represents a 12 x 1 vector which is a frequency-domain signalafter DFT processing of

$\begin{bmatrix}s_{N} \\s_{N}\end{bmatrix}$

.

In this case, when the DMRS sequence is transmitted by theDFT-spread-OFDM scheme, a DFT computation is performed by using a formin which the length-6 sequence is repeated twice in the pre-DFT step asmentioned above at the time of transmitting a single-port DMRS.

When the number of DMRS ports is 2, a specific DMRS port may beconfigured in a comb-2 type in which a frequency offset is 0 and theother DMRS port may be configured in a comb-2 type in which thefrequency offset is 1. In this case, when the length-6 sequence to beused in the second DMRS port and the length-6 sequence to be used in thefirst DMRS port are mapped to a frequency axis through a (pre-)DFTprocess as shown in Equation 8 above, both the length-6 sequences areallocated to a Comb-2 structure (comb-2 structure in which the frequencyoffset is 0) having the same frequency offset. Accordingly, when bothDMRS ports are used, a shifting operation on the frequency axis may beadditionally required. However, in this case, since the additionalshifting operation is required, the two-port DMRS sequence may betransmitted/configured to single symbols through different (even andodd) Comb-2 by the following scheme.

Sequence transmitted to first DRMS port:

s_(S)⁽¹⁾ ∈ C^(6 × 1)(6 × 1vector)

Sequence transmitted to second DRMS port:

s_(N)⁽²⁾ ∈ C^(6 × 1)(6 × 1vector)

The sequence may be a different sequence or the same sequence selectedin the length-6 DMRS sequence table.

In order to transmit the sequences transmitted in both DMRS portsthrough different Comb-2, the sequence transmitted to the first DRMaport is multiplied by the DFT matrix in the form of

[_(s_(N)⁽¹⁾)^(s_(N)⁽¹⁾)]

for the (pre-)DFT processing (the DFT processing is performed) and inthe case of the second DMRS port, the (pre-)DFT processing may beperformed in the form of

[_(−s_(N)⁽⁰⁾)^(s_(N)⁽²⁾)]

and/or

[_(+s_(N)⁽²⁾)^(−s_(N)⁽⁰⁾)]

. Consequently, for the sequence transmitted to the second DMRS port,even though additional shifting processing is not performed after DFTprocessing, a non-zero value is configured/transmitted to sixodd-numbered REs as the frequency offset is set to 1 and a or thenon-zero value is mapped/transmitted to six even-numbered REs.

For first DMRS port:

$x_{2N} = D_{DFT}\begin{bmatrix}S_{N} \\S_{N}\end{bmatrix}$

For second DMRS port:

$x_{2N} = D_{DFT}\begin{bmatrix}S_{N} \\{- S_{N}}\end{bmatrix}\mspace{6mu}\text{or}x_{2N} = D_{DFT}\begin{bmatrix}{- S_{S}} \\S_{N}\end{bmatrix}$

In the scheme, the sequences transmitted to both ports, respectively areorthogonal to each other on the frequency axis even though time-domainOCC is not configured at the (pre-)DFT end, the sequences aredistinguished. In other words, different sequences may be mapped (orconfigured or transmitted) to both DMRS ports.

For reference, the first and second DMRS ports mentioned in the presentdisclosure mean different DMRS ports and are independent of a DMRS portindex.

In Methods 2, 2-1, and 2-2 mentioned above, a frequency RE mappingmatrix is multiplied after DFT in order to map two antenna ports (e.g.,two DMRS antenna ports) onto the frequency axis through two Comb-2structures.

In Methods 2, 2-1, and 2-2, two different antenna ports may beconsidered and a case may be considered in which Method 6 above is usedfor Comb-2 type frequency RE mapping for each antenna port.

In other words, referring to Equations 11 and 12 of Method 6, length-6sequences transmitted to first and second antenna ports after pre-DFTare allocated to a frequency RE in which the frequency offset is “0” anda frequency RE in which the frequency offset is “1”, respectively. Byconsidering Method 6 above, Method 2-3 below is proposed similarly toMethod 2-2.

Hereinafter, an additional embodiment for Method 2 described above willbe described through Method 2-3.

Method 2-3

Method 2-3 relates to a method in which all sequences presented in Table15 are used, in which each sequence element is constituted by 15-(PhaseShift Keying (PSK) symbols and the length is 6 or some of the sequencespresented in Table 15 are used as uplink PUSCH and/or PUCCH DMRSsequences.

The proposed sequences may be used for Discrete Fourier Transform SpreadOrthogonal Frequency Division Multiplexing (DFT-s-OFDM) and/or CyclicPrefix OFDM (CP-OFDM). In the case of Method 2-3, since N=6 and M=8, thetotal number of sequences which may be considered is 8⁶. Here, a totalof two antenna ports (e.g., two DMRa antenna ports) are considered andeach antenna port is subject to Frequency Division Multiplexing (FDM) inthe form of Comb-2.

In this case, in order to map the lengt_(l1)-6 sequences of two antennaports through the Comb-2 structure, like equation 11 and equation 12 ofmethod 6 above, the length-6 sequence of the first port is repeatedtwice and the length-6 sequence of the second port is repeatedly outputby changing a sign.

A rule of generating (or choosing or using) K (> 0) some sequences amonga total of sequences is as follows. Here, K = 45 is assumed.

A main feature of the proposed sequence is that two antenna portssubject to FDM in the form of Comb-2 show a low PAPR characteristic of2.2 dB or less when the FDSS filter (FDSS filter in which thetime-domain response is [0.28 1 0.28]) is applied and a low PAPRcharacteristic of 2.9 dB even when the FDSS filter is not applied.

Additionally, the proposed sequence has the following characteristics.

-   The proposed sequence has a characteristic that the maximum cyclic    auto-correlation is equal to or smaller than approximately 0.2357 in    +1 and -1 cyclic auto-correlation.-   The proposed sequence has a characteristic that the maximum cyclic    auto-correlation is equal to or smaller than approximately 0.85 in    +3, +2, +1, -1, -2, and -3 cyclic auto-correlation lags.-   Among K chosen sequences, all available cyclic shifted forms of a    specific length-N sequence may be regarded as the same sequence.    Accordingly, among K chosen sequences, no specific sequence is the    same as an available cyclic shifted form of another sequence.

TABLE 14 index u Sequences ɸ_(u) (n) PAPR [dB] under FDSS filter for the1^(st) port PAPR [dB] under FDSS filter for the 2^(nd) port PAPR [dB]without FDSS filter for the 1^(st) port PAPR [dB] without FDSS filterfor the 2^(nd) port 1 -7 -7 3 7 -5 5 1.5699 2.0795 2.6332 2.2218 2 -7 -5-1 -7 5 -1 2.1235 1.9930 2.8984 2.1349 3 -7 -5 -1 5 1 -5 1.9058 1.82462.4184 1.6003 4 -7 -5 -1 5 1 -3 2.1617 2.0738 2.5641 2.4144 5 -7 -5 5 1-7 -3 1.8689 1.9449 2.1792 1.6280 6 -7 -5 5 1 -5 -3 1.7645 1.9261 2.44941.3633 7 -7 -5 5 1 -5 -1 1.0700 1.9930 2.4013 2.1349 8 -7 -5 5 1 7 -51.9941 1.4471 2.8754 2.2516 9 -7 -3 -1 -7 5 -1 2.0060 1.9261 2.52741.3633 10 -7 -3 -1 3 -1 -5 2.0580 2.0726 2.8206 2.4402 11 -7 -3 -1 5 1-5 2.1968 1.8320 1.7589 1.7234 12 -7 -3 -1 7 3 -3 1.7644 2.1163 2.13362.1126 13 -7 -3 1 -5 7 3 1.3980 1.9740 1.4299 1.8975 14 -7 -3 1 7 3 -11.4188 1.9609 1.3790 1.9672 15 -7 -3 5 1 -5 -3 1.8753 1.9562 2.15271.6412 16 -7 -3 7 3 -3 -1 1.0858 1.9763 2.4351 2.1548 17 -7 -3 7 3 -1 31.5866 2.0603 2.7305 2.8314 18 -7 -1 3 -7 5 3 2.0574 1.9619 2.83292.1978 19 -7 3 -1 -7 -5 -1 2.0154 1.9050 2.4374 1.3575 20 -7 3 -1 -7 -3-1 2.1603 1.9619 2.8474 2.1978 21 -7 3 -1 5 -7 -5 1.9133 1.8229 2.50311.6731 22 -7 3 -1 5 7 -5 2.1908 1.8229 1.7415 1.7723 23 -7 3 -1 7 -7 -31.7619 2.1268 2.1823 2.0435 24 -7 3 -1 7 -5 -3 1.8269 1.9568 2.88231.1442 25 -7 3 5 7 -5 5 1.6755 1.9763 2.4312 2.1548 26 -7 3 7 -7 -5 51.6696 1.9930 2.3269 2.1349 27 -7 3 7 -5 5 5 1.5402 2.0839 2.5659 2.198028 -7 3 7 7 -5 5 1.4371 1.6616 2.4208 1.9350 29 -7 5 -7 -3 3 -1 1.27152.0482 2.2025 2.8895 30 -7 5 -7 -3 7 3 2.1954 2.0738 2.8917 2.4144 31 -75 -5 -1 3 -1 1.3007 2.0603 2.2771 2.8314 32 -7 5 -3 3 1 5 2.0901 2.14032.8433 2.7642 33 -7 5 1 -5 -1 3 1.4188 1.9609 1.3790 1.9672 34 -7 5 1 57 -5 2.0363 2.0738 2.7382 2.4144 35 -7 5 1 7 -5 -3 2.1387 2.0726 2.65922.4402 36 -7 5 1 7 -5 -1 1.3980 1.9740 1.4299 1.8975 37 -7 7 -5 1 -3 71.9941 1.7210 2.8754 2.3917

Table 14 shows one example of the proposed 8-PSK based sequence set(length-6) and the modulation symbols are generated by

s_(u)(n) = e^(jϕ_(u)(n)π/8)

. The PAPR performance is generated in the DFT-s-OFDM system havingComb-2 type DMRS for one resource block (RB) (TS 38.211, TS 38.214, andTS 38.331 are referred to for Comb-2 type DMRS).

-   The modulation symbols are generated by-   $s_{u}(n) = e^{\frac{j\phi_{\text{u}}{(\text{n})}\text{π}}{8}}$-   .-   u: Sequence index-   n: Element index of each sequence)-   The applied FDSS filter corresponds to the time-domain response of    [0.28 1.0 0.28].-   An IFFT size is 64 and a DFT size is 12.

Some or all of the sequences presented in Table 14 above may be used.

Further, some or all of the sequences presented in Table 14 above andsequences (having different characteristics) not presented in Table 14above table and one sequence set may be constituted and used. It may beconsidered that such a constitution as an extension (or application) ofthe method proposed in the present disclosure is included in the spiritof the method proposed in the present disclosure.

FIG. 19 illustrates PAPR performance for a proposed set of length-6sequences in which elements of each sequence are constituted by 8-PSKsymbols.

Low-PAPR Sequence Generation Type 2

Additionally, low-PAPR sequence generation type 2 will be described inbrief.

A low-PAPR sequence

r_(u, v)^((α, δ))(n)

may be defined by a base sequence

${\overline{r}}_{u,\, v}(n)$

according to Equation 13 below.

$r_{u,v}^{({a,\hat{a}})}(n) = {\overline{r}}_{u,v}(n),\mspace{6mu}\,\mspace{6mu} 0 \leq n < M$

Here,

M = mN_(wu)^(R8)/2^(δ)

represents the length of the sequence. Multiple sequences are definedfrom a single base sequence through different values of α and δ.

Base sequences

${\overline{r}}_{u,\, v}(n)$

are divided into groups and here, u ∈ (0, 1, ...,29) represents a groupnumber and v represents a base sequence number in the group. Each groupincludes one base sequence v=0 having a length of

M = mN_(uv)^(RB)/2^(δ), 1/2 ≤ m/2^(δ)

. A sequence

${\overline{r}}_{u,v}(0),...,{\overline{r}}_{u,v}\left( {M - 1} \right)$

is defined by Equation 14 below.

${\overline{r}}_{u,v}(n) = \frac{1}{\sqrt{M}}{\sum\limits_{j = 0}^{M - 1}{{\widetilde{r}}_{u,v}(i)e^{- j\frac{2\min}{M}}}}$

n = 0, ..., M − 1

Here, a definition

${\overline{r}}_{u,v}(l)$

of depends on the sequence length.

Low-PAPR sequence generation type 2 above may be divided into (1)sequences having length 30 or larger and (2) sequences having a lengthless than 30.

The sequences having the length less than 30 will be described in brief.

Sequences of length less than 30

The sequence

r̃_(u, v)(l)

is given by Equation 15 below for M = 6.

r̃_(u, v)(i) = e^(jφ(i)π/8), 0 ≤ i ≤ M − 1

Here, a value of

φ(l)

may be given as shown in the above described tables.

The sequence

r̃_(u, v)(l)

is obtained by complex value modulation symbols due to π/2-BPSKmodulation for M ∈ (12, 18, 24).

Contents regarding low-PAPR sequence generation type 2 above may beapplied to the methods proposed in the present disclosure, which aredescribed above.

The methods, embodiments, and descriptions for implementing the proposalin the present disclosure, which are described above may be separatelyapplied or one or more methods, embodiments, and descriptions may becombined and applied.

FIG. 20 is a flowchart illustrating an example of a method fortransmitting a demodulation reference signal for uplink data in thepresent disclosure.

More specifically, a terminal receives, from a base station, a radioresource control (RRC) signaling including control informationrepresenting that transform precoding for uplink has been enabled, inS2010.

The terminal generates a low peak to average power ratio (PAPR) sequencebased on a length-6 sequence, in S2020.

The terminal generates a sequence used for the demodulation referencesignal based on the low PAPR sequence, in S2030.

The terminal transmits, to the base station, the demodulation referencesignal based on the sequence used for the demodulation reference signal,in S2040.

Here, the length-6 sequence may have an 8-phase shift keying (PSK)symbol as each element of the sequence.

The length-6 sequence may be determined by

e^(jφ(i)π/8)

, and the i may be an index of elements of the length-6 sequence.

Here, a value of the

φ(i)

may comprise (-1 -7 -3 -5 -1 3), (-7 3 -7 5 -7 -3), (5 -7 7 1 5 1), (-73 1 5 -1 3), (-7 -5 -1 -7 -5 5), (-7 1 -3 3 7 5) and (-7 1 -3 1 5 1).

A sequence which is cyclic shifted for the

φ(i)

may be a same sequence with the

φ(i)

.

A number of possible value of the

φ(i)

may be 8⁶.

A value of an auto-correlation for the low PAPR sequence may be lessthan a specific value.

In addition, the terminal may apply a frequency domain spectrum shaping(FDSS) filter to the low PAPR sequence

The low PAPR sequence may be frequency division multiplexed (FDM) for 2antenna ports as a Comb-2 form.

The low PAPR sequence which is used for each of the 2 antenna ports maybe different for each other.

Detailed operations where the method illustrated in FIG. 20 isimplemented in the wirelsss device are described.

A terminal may include a transceiver configured to transmit and receiveradio signals; and a processor operatively coupled to the transceiver,in order to transmit a demodulation reference signal (DMRS) for uplinkdata in a wireless communication system.

The processor of the terminal may be configured to receive, from a basestation, a radio resource control (RRC) signaling including controlinformation representing that transform precoding for uplink has beenenabled, generate a low peak to average power ratio (PAPR) sequencebased on a length-6 sequence, generate a sequence used for thedemodulation reference signal based on the low PAPR sequence, andtransmit, to the base station, the demodulation reference signal basedon the sequence used for the demodulation reference signal.

Example of Communication System to Which Present Disclosure is Applied

Although not limited thereto, but various descriptions, functions,procedures, proposals, methods, and/or operation flowcharts of thepresent disclosure, which are disclosed in this document may be appliedto various fields requiring wireless communications/connections (e.g.,5G) between devices.

Hereinafter, the communication system will be described in more detailwith reference to drawings. In the following drawings/descriptions, thesame reference numerals will refer to the same or corresponding hardwareblocks, software blocks, or functional blocks if not differentlydescribed.

FIG. 21 illustrates a communication system applied to the presentdisclosure.

Referring to FIG. 21 , a communication system 1 applied to the presentdisclosure includes a wireless device, an eNB, and a network. Here, thewireless device may mean a device that performs communication by using awireless access technology (e.g., 5G New RAT (NR) or Long Term Evolution(LTE)) and may be referred to as a communication/wireless/5G device.Although not limited thereto, the wireless device may include a robot100 a. vehicles 100b-1 and 100b-2, an extended Reality (XR) device 100c, a hand-held device 100 d, a home appliance 100 e, an Internet ofThing (loT) device 100 f, and an Al device/server 400. For example, thevehicle may include a vehicle with a wireless communication function, anautonomous driving vehicle, a vehicle capable of performinginter-vehicle communication, and the like. Here, the vehicle may includean Unmanned Aerial Vehicle (UAV) (e.g., drone). The XR device mayinclude an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality(MR) device and may be implemented as a form such as a head-mounteddevice (HMD), a head-up display (HUD) provided in the vehicle, atelevision, a smart phone, a computer, a wearable device, a homeappliance device, digital signage, a vehicle, a robot, etc. Thehand-held device may include the smart phone, a smart pad, a wearabledevice (e.g., a smart watch, a smart glass), a computer (e.g., anotebook, etc.), and the like. The home appliance device may include aTV, a refrigerator, a washing machine, and the like. The loT device mayinclude a sensor, a smart meter, and the like. For example, the eNB andthe network may be implemented even the wireless device and a specificwireless device 200 a may operate an eNB/network node for anotherwireless device.

The wireless devices 100 a to 100 f may be connected to a network 300through an eNB 200. An artificial intelligence (Al) technology may beapplied to the wireless devices 100 a to 100 f and the wireless devices100 a to 100 f may be connected to an Al server 400 through the network300. The network 300 may be configured by using a 3G network, a 4G(e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices100 a to 100 f may communicate with each other through the eNB200/network 300, but may directly communicate with each other withoutgoing through the eNB/network (sidelink communication). For example, thevehicles 100b-1 and 100b-2 may perform direct communication (e.g.,Vehicle to Vehicle (V2V)/Vehicle to everything (V2X) communication).Further, the loT device (e.g., sensor) may perform direct communicationwith other loT devices (e.g., sensor) or other wireless devices 100 a to100 f.

Wireless communications/connections 150 a, 150 b, and 150 c may be madebetween the wireless devices 100 a to 100 f and the eNB 200 and betweenthe eNB 200 and the eNB 200. Here, the wireless communication/connectionmay be made through various wireless access technologies (e.g., 5G NR)such as uplink/downlink communication 150 a, sidelink communication 150b (or D2D communication), and inter-eNB communication 150 c (e.g.,relay, Integrated Access Backhaul (IAB). The wireless device and theeNB/the wireless device and the eNB and the eNB may transmit/receiveradio signals to/from each other through wirelesscommunications/connections 150 a, 150 b, and 150 c. For example, thewireless communications/connections 150 a, 150 b, and 150 c maytransmit/receive signals through various physical channels. To this end,based on various proposals of the present disclosure, at least some ofvarious configuration information setting processes, various signalprocessing processes (e.g., channel encoding/decoding,modulation/demodulation, resource mapping/demapping, etc.), a resourceallocation process, and the like for transmission/reception of the radiosignal may be performed.

Example of Wireless Device to Which Present Disclosure Is Applied

FIG. 22 illustrates a wireless device which may be applied to thepresent disclosure.

Referring to FIG. 22 , a first wireless device 100 and a second wirelessdevice 200 may transmit/receive radio signals through various wirelessaccess technologies (e.g., LTE and NR). Here, the first wireless device100 and the second wireless device 200 may correspond to a wirelessdevice 100 x and an eNB 200 and/or a wireless device 100 x and awireless device 100 x of FIG. 21 .

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor 102 maycontrol the memory 104 and/or the transceiver 106 and may be configuredto implement descriptions, functions, procedures, proposals, methods,and/or operation flows disclosed in the present disclosure. For example,the processor 102 may process information in the memory 104 and generatea first information/signal and then transmit a radio signal includingthe first information/signal through the transceiver 106. Further, theprocessor 102 may receive a radio signal including a secondinformation/signal through the transceiver 106 and then store in thememory 104 information obtained from signal processing of the secondinformation/signal. The memory 104 may connected to the processor 102and store various information related to an operation of the processor102. For example, the memory 104 may store a software code includinginstructions for performing some or all of processes controlled by theprocessor 10 or performing the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in the presentdisclosure. Here, the processor 102 and the memory 104 may be a part ofa communication modem/circuit/chip designated to implement the wirelesscommunication technology (e.g., LTE and NR). The transceiver 106 may beconnected to the processor 102 and may transmit and/or receive the radiosignals through one or more antennas 108. The transceiver 106 mayinclude a transmitter and/or a receiver. The transceiver 106 may bemixed with a radio frequency (RF) unit. In the present disclosure, thewireless device may mean the communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor 202may control the memory 204 and/or the transceiver 206 and may beconfigured to implement descriptions, functions, procedures, proposals,methods, and/or operation flows disclosed in the present disclosure. Forexample, the processor 202 may process information in the memory 204 andgenerate a third information/signal and then transmit a radio signalincluding the third information/signal through the transceiver 206.Further, the processor 202 may receive a radio signal including a fourthinformation/signal through the transceiver 206 and then store in thememory 204 information obtained from signal processing of the fourthinformation/signal. The memory 204 may connected to the processor 202and store various information related to an operation of the processor202. For example, the memory 204 may store a software code includinginstructions for performing some or all of processes controlled by theprocessor 202 or performing the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in the presentdisclosure. Here, the processor 202 and the memory 204 may be a part ofa communication modem/circuit/chip designated to implement the wirelesscommunication technology (e.g., LTE and NR). The transceiver 206 may beconnected to the processor 202 and may transmit and/or receive the radiosignals through one or more antennas 208. The transceiver 206 mayinclude a transmitter and/or a receiver and the transceiver 206 may bemixed with the RF unit. In the present disclosure, the wireless devicemay mean the communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described in more detail. Although not limited thereto, one or moreprotocol layers may be implemented by one or more processors 102 and202. For example, one or more processors 102 and 202 may implement oneor more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). One or more processors 102 and 202 may generate one ormore protocol data units (PDUs) and/or one or more service data units(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operation flowcharts disclosed in the presentdisclosure. One or more processors 102 and 202 may generate a message,control information, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in the present disclosure. One or more processors 102 and 202may generate a signal (e.g., a baseband signal) including the PDU, theSDU, the message, the control information, the data, or the informationaccording to the function, the procedure, the proposal, and/or themethod disclosed in the present disclosure and provide the generatedsignal to one or more transceivers 106 and 206. One or more processors102 and 202 may receive the signal (e.g. baseband signal) from one ormore transceivers 106 and 206 and acquire the PDU, the SDU, the message,the control information, the data, or the information according to thedescriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in the present disclosure.

One or more processors 102 and 202 may be referred to as a controller, amicrocontroller, a microprocessor, or a microcomputer. One or moreprocessors 102 and 202 may be implemented by hardware, firmware,software, or a combination thereof. As one example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in one or moreprocessors 102 and 202. The descriptions, functions, procedures,proposals, and/or operation flowcharts disclosed in the presentdisclosure may be implemented by using firmware or software and thefirmware or software may be implemented to include modules, procedures,functions, and the like. Firmware or software configured to perform thedescriptions, functions, procedures, proposals, and/or operationflowcharts disclosed in the present disclosure may be included in one ormore processors 102 and 202 or stored in one or more memories 104 and204 and driven by one or more processors 102 and 202. The descriptions,functions, procedures, proposals, and/or operation flowcharts disclosedin the present disclosure may be implemented by using firmware orsoftware in the form of a code, the instruction and/or a set form of theinstruction.

One or more memories 104 and 204 may be connected to one or moreprocessors 102 and 202 and may store various types of data, signals,messages, information, programs, codes, instructions, and/orinstructions. One or more memories 104 and 204 may be configured by aROM, a RAM, an EPROM, a flash memory, a hard drive, a register, a cachememory, a computer reading storage medium, and/or a combination thereof.One or more memories 104 and 204 may be positioned inside and/or outsideone or more processors 102 and 202. Further, one or more memories 104and 204 may be connected to one or more processors 102 and 202 throughvarious technologies such as wired or wireless connection.

One or more transceivers 106 and 206 may transmit to one or more otherdevices user data, control information, a wireless signal/channel, etc.,mentioned in the methods and/or operation flowcharts of the presentdisclosure. One or more transceivers 106 and 206 may receive from one ormore other devices user data, control information, a wirelesssignal/channel, etc., mentioned in the descriptions, functions,procedures, proposals, methods, and/or operation flowcharts disclosed inthe present disclosure. For example, one or more transceivers 106 and206 may be connected to one or more processors 102 and 202 and transmitand receive the radio signals. For example, one or more processors 102and 202 may control one or more transceivers 106 and 206 to transmit theuser data, the control information, or the radio signal to one or moreother devices. Further, one or more processors 102 and 202 may controlone or more transceivers 106 and 206 to receive the user data, thecontrol information, or the radio signal from one or more other devices.Further, one or more transceivers 106 and 206 may be connected to one ormore antennas 108 and 208 and one or more transceivers 106 and 206 maybe configured to transmit and receive the user data, controlinformation, wireless signal/channel, etc., mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in the present disclosure through one ormore antennas 108 and 208. In the present disclosure one or moreantennas may be a plurality of physical antennas or a plurality oflogical antennas (e.g., antenna ports). One or more transceivers 106 and206 may convert the received radio signal/channel from an RF band signalto a baseband signal in order to process the received user data, controlinformation, radio signal/channel, etc., by using one or more processors102 and 202. One or more transceivers 106 and 206 may convert the userdata, control information, radio signal/channel, etc., processed byusing one or more processors 102 and 202, from the baseband signal intothe RF band signal. To this end, one or more transceivers 106 and 206may include an (analog) oscillator and/or filter.

Example of Signal Processing Circuit to Which Present Disclosure isApplied

FIG. 23 illustrates a signal processing circuit applied to the presentdisclosure.

Referring to FIG. 23 a signal processing circuit 1000 may include ascrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040,a resource mapper 1050, and a signal generator 1060. Although notlimited thereto, an operation/function of FIG. 23 may be performed bythe processors 102 and 202 and/or the transceivers 106 and 206 of FIG.22 . Hardware elements of FIG. 23 may be implemented in the processors102 and 202 and/or the transceivers 106 and 206 of FIG. 22 . Forexample, blocks 1010 to 1060 may be implemented in the processors 102and 202 of FIG. 22 . Further, blocks 1010 to 1050 may be implemented inthe processors 102 and 202 of FIG. 17 and the block 1060 of FIG. 22 andthe block 2760 may be implemented in the transceivers 106 and 206 ofFIG. 22 .

A codeword may be transformed into a radio signal via the signalprocessing circuit 1000 of FIG. 23 . Here, the codeword is an encodedbit sequence of an information block. The information block may includetransport blocks (e.g., a UL-SCH transport block and a DL-SCH transportblock). The radio signal may be transmitted through various physicalchannels (e.g., PUSCH and PDSCH).

Specifically, the codeword may be transformed into a bit sequencescrambled by the scrambler 1010. A scramble sequence used for scramblingmay be generated based on an initialization value and the initializationvalue may include ID information of a wireless device. The scrambled bitsequence may be modulated into a modulated symbol sequence by themodulator 1020. A modulation scheme may include pi/2-BPSK(pi/2-BinaryPhase Shift Keying), m-PSK(m-Phase Shift Keying), m-QAM(m-QuadratureAmplitude Modulation), etc. A complex modulated symbol sequence may bemapped to one or more transport layers by the layer mapper 1030.Modulated symbols of each transport layer may be mapped to acorresponding antenna port(s) by the precoder 1040 (precoding). Output zof the precoder 1040 may be obtained by multiplying output y of thelayer mapper 1030 by precoding matrix W of N * M. Here, N represents thenumber of antenna ports and M represents the number of transport layers.Here, the precoder 1040 may perform precoding after performing transformprecoding (e.g., DFT transform) for complex modulated symbols. Further,the precoder 1040 may perform the precoding without performing thetransform precoding.

The resource mapper 1050 may map the modulated symbols of each antennaport to a time-frequency resource. The time-frequency resource mayinclude a plurality of symbols (e.g., CP-OFDMA symbol and DFT-s-OFDMAsymbol) in a time domain and include a plurality of subcarriers in afrequency domain. The signal generator 1060 may generate the radiosignal from the mapped modulated symbols and the generated radio signalmay be transmitted to another device through each antenna. To this end,the signal generator 1060 may include an Inverse Fast Fourier Transform(IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-AnalogConverter (DAC), a frequency uplink converter, and the like.

A signal processing process for a receive signal in the wireless devicemay be configured in the reverse of the signal processing process (1010to 1060) of FIG. 23 . For example, the wireless device (e.g., 100 or 200of FIG. 22 ) may receive the radio signal from the outside through theantenna port/transceiver. The received radio signal may be transformedinto a baseband signal through a signal reconstructer. To this end, thesignal reconstructer may include a frequency downlink converter, ananalog-to-digital converter (ADC), a CP remover, and a Fast FourierTransform (FFT) module. Thereafter, the baseband signal may bereconstructed into the codeword through a resource de-mapper process, apostcoding process, a demodulation process, and a de-scrambling process.The codeword may be reconstructed into an original information block viadecoding. Accordingly, a signal processing circuit (not illustrated) forthe receive signal may include a signal reconstructer, a resourcedemapper, a postcoder, a demodulator, a descrambler, and a decoder.

Utilization Example of Wireless Device to Which Present Disclosure isApplied

FIG. 24 illustrates another example of a wireless device applied to thepresent disclosure.

The wireless device may be implemented as various types according to ause example/service (see FIG. 21 ). Referring to FIG. 24 , wirelessdevices 100 and 200 may correspond to the wireless devices 100 and 200of FIG. 22 and may be constituted by various elements, components,units, and/or modules. For example, the wireless devices 100 and 200 mayinclude a communication unit 110, a control unit 120, and a memory unit130, and an additional element 140. The communication unit may include acommunication circuit 112 and a transceiver(s) 114. For example, thecommunication circuit 112 may include one or more processors 102 and 202and/or one or more memories 104 and 204 of FIG. 22 . For example, thetransceiver(s) 114 may include one or more transceivers 106 and 206and/or one or more antennas 108 and 208 of FIG. 22 . The control unit120 is electrically connected to the communication unit 110, the memoryunit 130, and the additional element 140 and controls an overalloperation of the wireless device. For example, the control unit 120 mayan electrical/mechanical operation of the wireless device based on aprogram/code/instruction/information stored in the memory unit 130.Further, the control unit 120 may transmit the information stored in thememory unit 130 to the outside (e.g., other communication devices)through the communication unit 110 via a wireless/wired interface orstore information received from the outside (e.g., other communicationdevices) through the wireless/wired interface through the communicationunit 110.

The additional element 140 may be variously configured according to thetype of wireless device. For example, the additional element 140 mayinclude at least one of a power unit/battery, an input/output (I/O)unit, a driving unit, and a computing unit. Although not limitedthereto, the wireless device may be implemented as a form such as therobot 100 a of FIG. 21 , the vehicles 100 b-1 and 100 b-2 of FIG. 21 ,the XR device 100 c of FIG. 21 , the portable device 100 d of FIG. 21 ,the home appliance 100 e of FIG. 212 , the loT device 100 f of FIG. 21 ,a digital broadcasting terminal, a hologram device, a public safetydevice, an MTC device, a medical device, a fintech device (or financialdevice), a security device, a climate/environment device, an Alserver/device 400 of FIG. 21 , the eNB 200 of FIG. 21 , a network node,etc. The wireless device may be movable or may be used at a fixed placeaccording to a use example/service.

In FIG. 24 , all of various elements, components, units, and/or modulesin the wireless devices 100 and 200 may be interconnected through thewired interface or at least may be wirelessly connected through thecommunication unit 110. For example, the control unit 120 and thecommunication 110 in the wireless devices 100 and 200 may be wiredlyconnected and the control unit 120 and the first unit (e.g., 130 or 140)may be wirelessly connected through the communication unit 110. Further,each element, component, unit, and/or module in the wireless devices 100and 200 may further include one or more elements. For example, thecontrol unit 120 may be constituted by one or more processor sets. Forexample, the control unit 120 may be configured a set of a communicationcontrol processor, an application processor, an electronic control unit(ECU), a graphic processing processor, a memory control processor, etc.As another example, the memory 130 may be configured as a random accessmemory (RAM), a dynamic RAM (DRAM), a read only memory (ROM), a flashmemory, a volatile memory, a non-volatile memory, and/or combinationsthereof.

Example of Portable Device to Which Present Disclosure Is Applied

FIG. 25 illustrates a portable device applied to the present disclosure.

The portable device may include a smart phone, a smart pad, a wearabledevice (e.g., a smart watch, a smart glass), and a portable computer(e.g., a notebook, etc.). The portable device may be referred to as aMobile Station (MS), a user terminal (UT), a Mobile Subscriber Station(MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or aWireless terminal (WT).

Referring to FIG. 25 , a portable device 100 may include an antenna unit108, a communication unit 110, a control unit 120, a memory unit 130, apower supply unit 140 a, an interface unit 140 b, and an input/outputunit 140 c. The antenna unit 108 may be configured as a part of thecommunication unit 110. The blocks 110 to 130/140 a to 140 c correspondto the blocks 110 to 130/140 of FIG. 24 , respectively.

The communication unit 110 may transmit/receive a signal (e.g., data, acontrol signal, etc.) to/from another wireless device and eNBs. Thecontrol unit 120 may perform various operations by controllingcomponents of the portable device 100. The control unit 120 may includean Application Processor (AP). The memory unit 130 may storedata/parameters/programs/codes/instructions required for driving theportable device 100. Further, the memory unit 130 may store input/outputdata/information, etc. The power supply unit 140 a may supply power tothe portable device 100 and include a wired/wireless charging circuit, abattery, and the like. The interface unit 140 b may support a connectionbetween the portable device 100 and another external device. Theinterface unit 140 b may include various ports (e.g., an audioinput/output port, a video input/output port) for the connection withthe external device. The input/output unit 140 c may receive or output avideo information/signal, an audio information/signal, data, and/orinformation input from a user. The input/output unit 140 c may include acamera, a microphone, a user input unit, a display unit 140 d, aspeaker, and/or a haptic module.

As one example, in the case of data communication, the input/output unit140 c may acquire information/signal (e.g., touch, text, voice, image,and video) input from the user and the acquired information/signal maybe stored in the memory unit 130. The communication unit 110 maytransform the information/signal stored in the memory into the radiosignal and directly transmit the radio signal to another wireless deviceor transmit the radio signal to the eNB. Further, the communication unit110 may receive the radio signal from another wireless device or eNB andthen reconstruct the received radio signal into originalinformation/signal. The reconstructed information/signal may be storedin the memory unit 130 and then output in various forms (e.g., text,voice, image, video, haptic) through the input/output unit 140 c.

In the embodiments described above, the components and the features ofthe present disclosure are combined in a predetermined form. Eachcomponent or feature should be considered as an option unless otherwiseexpressly stated. Each component or feature may be implemented not to beassociated with other components or features. Further, the embodiment ofthe present disclosure may be configured by associating some componentsand/or features. The order of the operations described in theembodiments of the present disclosure may be changed. Some components orfeatures of any embodiment may be included in another embodiment orreplaced with the component and the feature corresponding to anotherembodiment. It is apparent that the claims that are not expressly citedin the claims are combined to form an embodiment or be included in a newclaim by an amendment after the application.

The embodiments of the present disclosure may be implemented byhardware, firmware, software, or combinations thereof. In the case ofimplementation by hardware, according to hardware implementation, theexemplary embodiment described herein may be implemented by using one ormore application specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,and the like.

In the case of implementation by firmware or software, the embodiment ofthe present disclosure may be implemented in the form of a module, aprocedure, a function, and the like to perform the functions oroperations described above. A software code may be stored in the memoryand executed by the processor. The memory may be positioned inside oroutside the processor and may transmit and receive data to/from theprocessor by already various means.

It is apparent to those skilled in the art that the present disclosuremay be embodied in other specific forms without departing from essentialcharacteristics of the present disclosure. Accordingly, theaforementioned detailed description should not be construed asrestrictive in all terms and should be considered to be exemplary. Thescope of the present disclosure should be determined by rationalconstruing of the appended claims and all modifications within anequivalent scope of the present disclosure are included in the scope ofthe present disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure is described based on an example applied to the3GPP LTE/LTE-A/NR system, but the present disclosure may be applied tovarious wireless communication systems in addition to the 3GPPLTE/LTE-A/NR system.

What is claimed is:
 1. A method of transmitting, by a terminal, ademodulation reference signal (DMRS) for a physical uplink controlchannel (PUCCH) in a wireless communication system, the methodcomprising: receiving a radio resource control (RRC) signaling includinginformation representing that transform precoding for the PUCCH isenabled; generating a low peak to average power ratio (PAPR) sequencebased on a base sequence, wherein the base sequence is based on alength-6 sequence; generating a sequence for the demodulation referencesignal based on the low PAPR sequence; and transmitting the demodulationreference signal based on the sequence, wherein the length-6 sequence isbased on e^(jφ(i)π/8), wherein the i is an index with a value from 0 to5, and wherein a set of values of (φ(0), φ(1), φ(2), φ(3), φ(4), φ(5))comprises (-7 3 1 5 -1 3), (-7 -5 -1 -7 -5 5), (-7 1 -3 3 7 5) and (-7 1-3 1 5 1).
 2. The method of claim 1, wherein the set of the values ofthe (φ(0), φ(1), φ(2), φ(3), φ(4), φ(5)) further comprises (-1 -7 -3 -5-1 3), (-7 3 -7 5 -7 -3), (5 -7 7 1 5 1).
 3. The method of claim 2,wherein, among a number of cases of the values of the (φ(0), φ(1), φ(2),φ(3), φ(4), φ(15)), a specific value of the (φ(0), φ(1), φ(2), φ(3),φ(4), φ(5))is not identical to any of a cyclic shifted value of anothervalue of the (φ(0), φ(1), φ(2), φ(3), φ(4), φ(5)).
 4. The method ofclaim 2, wherein the number of the cases of the values of the (φ(0),φ(1), φ(2), φ(3), φ(4), φ(5)) is
 30. 5. The method of claim 1, wherein avalue of an auto-correlation for the low PAPR sequence is less than aspecific value.
 6. The method of claim 1, further comprising: applying afrequency domain spectrum shaping (FDSS) filter to the low PAPRsequence.
 7. The method of claim 1, wherein the low PAPR sequence isfrequency division multiplexed (FDM) for 2 antenna ports as a Comb-2form.
 8. The method of claim 7, wherein the low PAPR sequence which isused for each of the 2 antenna ports is different for each other.
 9. Aterminal for transmitting a demodulation reference signal (DMRS) for aphysical uplink control channel (PUCCH) in a wireless communicationsystem, the terminal comprising: a transceiver configured to transmitand receive radio signals; and a processor operatively coupled to thetransceiver, wherein the processor controls to: receive a radio resourcecontrol (RRC) signaling including information representing thattransform precoding for the PUCCH is enabled; generate a low peak toaverage power ratio (PAPR) sequence based on a base sequence, whereinthe base sequence is based on a length-6 sequence; generate a sequencefor the demodulation reference signal based on the low PAPR sequence;and transmit the demodulation reference signal based on the sequence,wherein the length-6 sequence is based on e^(iφ(i)π/8), wherein the i isan index with a value from 0 to 5, and wherein a set of values of (φ(0),φ(1), φ(2), φ(3), φ(4), φ(5)) comprises (-7 3 1 5 -1 3), (-7 -5 -1 -7 -55), (-7 1 -3 3 7 5) and (-7 1 -3 1 5 1).
 10. The terminal of claim 9,wherein a value of the ^(φ(i)) further comprises (-1 -7 -3 -5 -1 3), (-73 -7 5 -7 -3), (5 -7 7 1 5 1).
 11. The terminal of claim 10, wherein,among possible value of the ^(φ(i)), a value of the ^(φ(i))is notidentical to any of a cyclic shifted value of another value ofthe^(φ(i)).
 12. The terminal of claim 9, wherein the processor furthercontrols to: apply a frequency domain spectrum shaping (FDSS) to the lowPAPR sequence.
 13. The method of claim 9, wherein the low PAPR sequenceis frequency division multiplexed (FDM) for 2 antenna ports as a Comb-2form.